The Video Revolution; Business, Broadcast, Surveillance, Security and Sales

From the upcoming book, “Caught On Video”

The world of video has become a way of life.  What once was a verbal society has become a visual society.  Humans began speaking, then advanced to writing.  The transmission of thoughts through speech became more advanced, too. The telegraph gave us the ability to communicate to others from a distance.  Radio then sent our thoughts over airwaves without wires. Images were projected using light onto screens that brought our thoughts to life! 

I don’t know about you, but I think this is all pretty amazing!

Video camera manufacturers had a vision that families would want a way to capture family events just like the previous decade had captured family events with movie cameras.  That is where I believe the video revolution began. Video camera manufacturers were right-- video cameras soon became present at nearly every major family event.

First there were movies, then television, and now many forms of video. Both analog and digital video has become a way of life in just about every private and public situation.  We use cameras at family events, to look at our drains for while doing home repairs, and for medical applications looking at the inside of our bodies.  We see cameras in public to patrol our streets to keep us safe; in stores, banks, sports arenas, and even on telephone poles to look at traffic conditions.

Video hit critical mass when Hollywood decided to use it as a medium to distribute movies. Much of what you see in theaters today is from high quality video projection--soon to become High Definition video projection--brought to the theater through wireless transmission. The advancement of video can seem to be moving faster than the speed of light.  

Today, surveillance CCTV (Closed circuit television systems) and PDA’s have joined in on the video revolution.  Cell phones can even record video at a moment’s notice.  To date, nearly every human activity has been caught on video at one time or another.  Executions and evangelism, sex, news, wars, crime, our kids growing up, and family vacations have all been caught on video.  As a nation, the United States has had front row seating for several major wars, court trials and even funerals like those of Princess Diana and Michael Jackson.

When Oasis singer Noel Gallagher was attacked on stage in Toronto in 2008, a great phenomenon occurred.  That night after the concert, dozens if not hundreds of videos recorded on cell phones of his on stage attack were posted on You Tube.

In a 2009blog post from YouTube, 20 hours of video are uploaded every minute.  People have made YouTube their online video home. This is the equivalent of Hollywood releasing over 86,000 new full-length movies into theaters each week.

Early television is like today’s modern digital videoconferencing. Two closed circuit television systems are connected by a wire or by dish and wireless transmission. I am sure you have seen news reporters broadcast from the scene of a crime or accident using this same technology.

This technology is also used for security today for closed circuit television systems. CCTV systems can be viewed live or recorded to a digital video recorder and viewed at a later date, just like television programming. Video is a great security tool.

Video as well as closed circuit television systems were traditionally recorded on VHS tape.  Today both systems use digital video recorders. DVR’s record video programming on a hard drive, very similar to computer hard drives. Often times that video information is transferred to DVD discs for viewing on other systems at later dates.  In the last ten years, video has served law enforcement, courts and private businesses very well.   

I am a huge video buff as well as a video forensic expert.  Much of the video that is presented in litigation stands by itself and a video forensic expert is not needed. However, litigators consult with video forensic experts when they feel something is just not right or they don’t understand some of the recorded information. Video forensic experts are educated, knowledgeable and experts at helping litigators understand the multi faceted aspect of video.

I have seen recorded video help litigation for over 17 years.  CCTV video has helped determine where a fire started, who the person was on the video recording at a certain time coordinate, and exactly how a slip and fall happened.

Video in the courtroom is a great aid when the truth about a situation needs to be discovered and understood. A video forensic expert’s activity is priceless when questions are asked about the operation of the CCTV system or when only a portion of the video footage is presented as evidence casting doubt on the prosecution or defense. Video does not lie, or does it?

I have been retained on cases for the defense where only a portion of available video footage was provided from a situation that was completely covered.  This works against the defense because part of the evidence is missing.  I have been asked by National Geographic to examine UFO footage. However, video alteration is not always distinctive and obvious.

Video is like a new language that we all need to speak going forward in 2012. It will entertain, educate, motivate, keep you safe, help your litigation and even grow your business. Take the time this year to learn a little about the power of video because we have truly hit the video revolution!

CCTV Camera Grid Solves Mystery

Whenever I am asked to review some CCTV system footage to help identify the activity and people in the footage, I begin with creating a camera grid.  A CCTV camera grid is a layout of all closed circuit cameras with their location and proximity to the activity and people in the recording.

There are several types of CCTV cameras, one of which is a point tilt zoom camera.  These PTZ cameras are made to follow the action as directed by their security (or loss prevention) operators.

In one case I was asked to review several cameras from a department store that covered a shop lifter.  Several of the cameras were an extremely high quality PTZ camera and actually followed the suspect around the store. Since the CCTV system was digital, the footage looked amazing and needed very little clarification.

What the case did need was a camera grid.  Working for the defense in this case, we had a series of events that needed to be determined that would help negotiate a plea.  So I set off to draw the store layout on a piece of paper and layout the cameras numbering them as I went. We were able to determine which cameras were in what area of the store so when the suspect passed through those areas a second time, we knew to look at the previous cameras for any other activity that could be seen outside of the main coverage area.

Then two great breaks came when we found camera shots in unlikely places that showed us a series of events as they actually occurred on other cameras in addition to the main camera in that specific coverage area.

By starting your video forensic examination with a camera grid, you can discover a lot more about your CCTV video footage than by simply relying on the obvious cameras for each series of events.

Lastly, keep in mind that nearby businesses like convenience stores and gas stations have exterior CCTV systems that may have video recordings that can help your case. A video forensic expert can enlarge and clarify footage that is in the distance that might help add evidence to support your case.  Remember, it’s about the preponderance of the evidence. All we have to do in any case is tip the scale slightly to address and establish a reasonable doubt. 

http://www.VideoForensicExpert.com

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Video Forensics, Junk Science or the Real Deal?

It seemed like a routine traffic stop…or was it? The police said they had probable cause, but did they? The video footage, retrieved from the very sophisticated, digital-video surveillance system mounted in the police car, shows tinted windows on the victim’s car; so how could the police see they had no seatbelts on? Bringing in a video forensic expert helped bring truth to the courtroom and prove scientifically that probable cause was not met, and the case was dismissed.
A bank robber thought the baseball cap would hide his face from the surveillance cameras, but the installation company for the closed-circuit television system (CCTV) had experience working with a video forensic expert who helped them figure out how to best position the cameras so all activity in the bank could be caught on video. The thief got away with $780 dollars, but was quickly apprehended and identified through the aid of an expert; he’s now serving seven years for the heist.

In a fatal shooting that was caught on surveillance video, the accuser’s face was identified for a brief second. With a few simple forensic video applications, like clarification and enlargement, as well as importing a frame from PhotoShop, the shooter was identified and brought to justice.

No longer a unique aid to deterring crime or capturing the criminal actions of the unsavory (as well as recording the mundane, casual incidents of everyday life), CCTV is now so pervasive, it can be found in locations from convenience stores to sports arenas, mall parking lots to traffic corners…even in doggy boarding camps where you can check on your family pet from your Blackberry or your computer.

While the protests are rampant that CCTV is a violation of our Constitutional right to privacy – especially given the many ways in which CCTV is now being used - there is no doubt that its value is embraced by litigators, police departments, security stations, airports and so on. With human resources stretched thin, video surveillance has become a critical tool in the war on crime, putting millions of extra “eyes” on the job, 24 hours a day, seven days a week.
But what happens once the perpetrator or action in question has been caught on video? What’s next? What transpires can often be a quagmire of “he saw, she saw,” with differences of opinion varying widely, with convincing arguments presented by both defense and prosecuting attorneys, and sometimes, a manipulation of the facts spinning in favor of one party versus another. This is where a video forensics expert can prove or disprove the layman’s observations, providing authoritative information or testimony based on a keen eye and knowledge of the technology.
Yet, many argue that forensic video technology is a “junk science,” a term used in this instance to label the practice as having no merit or credibility, that which cannot be authenticated, analyzed, or supported by scientific data. Science, by it’s very meaning, refers to that which can be proven systematically, and “junk”…well, that word is self-explanatory!

The main reasons forensic video technology is often branded a “junk science” are three-fold: First, there are no governing boards or licensing groups overseeing the video forensics profession, like you find in the legal or medical fields, for example. Because of this, theoretically, anyone could be touted as an expert, affecting the credibility and opinions of those with reputations previously held in high regard. Second, because video forensics is a complicated process and there are no standards on which to base testimony or proof – with no cohesiveness within the science itself – there can be wide gaps in opinions and observations. Third, because the technology and interpretation of video forensics (and audio) science can be difficult to understand by nonprofessionals, it’s often discounted as not having any value, especially by the side not presenting the video evidence in court.

Such is often the case in the courtroom where a Daubert motion can occur (in those states that have adopted its use). The word “Daubert” comes from an actual proceeding, taken from the U.S. Supreme Court’s Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) decision whereby the judges were directed to examine the scientific method beneath expert evidence, ruling what was scientifically relevant, reliable and admissible. In short, because of the Daubert case, The Supreme Court mandated that federal judges shall act as “gatekeepers” by deciding whether expert evidence be allowed before the jury.

If a Daubert motion is exercised, based on the Supreme Court’s opinion, the following is considered admissible scientific evidence: 1) evidence based on a theory or technique that can be tested; 2) the theory or technique has been reviewed by the expert’s peers; 3) the technique has a known error rate; and 4) there is general acceptance of the underlying science in the scientific community.

Where this can adversely affect the admissible testimony of a video forensics expert is that judges are expected to examine and understand the methods of the expert and determine whether or not they are qualified to testify. Since there are no clear guidelines on which to base such credible witnesses, in many cases judges are left to render an opinion without adequate knowledge of the science.

Because of this, a Daubert motion can be used by either side of the litigation table to exclude evidence made by an expert which might support other proof, or further incriminate.

In this scenario, I was required to answer questions proving I was qualified to give the court an expert opinion on audio evidence. This included verifying I was a certified digital video expert; that I’d completed several successful court cases; that I’d published articles to support my expertise; and so forth. Yet, the court deemed me unqualified to testify, thus proving there are always two sides to every court case; that rulings can be based less on experience and fact, and sometime more by a lack of understanding the scientific nature of video/audio forensics by the court.

In 2007 Kelly Gorham, a vibrant nursing student from a small town in Maine, missing for nearly a month, was found murdered, the result of strangulation, and buried in a shallow grave on property owned by the father of her ex-fiancé, Jason Twardus. Having been jilted by Gorham two months prior to her disappearance, Twardus is accused of killing Gorham in Maine and burying her in his native state of New Hampshire. Twardus’ alibi was inconsistent with some of the evidence found.

Flash-forward to late 2009 when the murder case goes to trial…and crucial evidence based on video footage hangs in the balance. Friends and family of Gorham believe Twardus is the man seen on surveillance footage from a convenience store in Colebrook, N.H. the day after Gorham was last seen alive. The store is only a few miles from where Gorham’s body was found. The footage shows a car that appears to be the same color and make as Twardus’ vehicle, and the image of a man Gorham’s family swears is her ex-fiancé (even though his face is not discernable) based on his posture, baggy clothing, profile and characteristic walk.

The prosecution brought in video forensic analyst Grant Fredericks to verify the family’s contention. After questioning Fredericks extensively on his background and qualifications, the defense attorney called video forensics, as a whole, “voodoo science” and a “pseudoscience.” Fredericks contested the defense’s viewpoint during testimony, citing his ability to analyze beyond that of a layperson’s eye.

In addition to other aspects cited, the affidavit Fredericks submitted to the court states there is a “strong likelihood” the car seen in the security footage is Twardus’ green Subaru Impreza, and that the sweatshirt the man was wearing is “consistent with in every respect” to a sweat shirt seized by police from Twardus’ home. “That man cannot be eliminated, in my opinion, as the man in the video,” Fredericks said. However, as of this writing, the defense filed a motion to suppress the testimony of Fredericks, which the judge is expected to rule on sometime in early 2010.

The courts that accept video evidence - supported by a video forensic expert - are usually those that involve an experienced trial attorney, with admissibility boiling down to the strength of the presenting attorney’s argument. When accepted, video evidence can help a judge or jury understand a crime scene or situation more clearly. Admissibility is stronger if a video forensic expert is involved.

In another milestone U.S. Supreme Court ruling, setting precedence for how video evidence may be decided on in a court case, consider the outcome of Scott v. Harris (2007), where appellate courts were given more freedom to decide issues on summary judgment. In a summary judgment practice a court generally considers the evidence to be more conducive to the nonmovant (a “nonmovant” refers to the party not filing a motion).

The eventual case of Scott v. Harris was preceded by a high-speed chase whereby a Georgia county deputy, on the tail of the speeding vehicle, was given permission from his supervisor to employ a PIT maneuver (allowing the patrol car to pull alongside the vehicle and force it to spin out or exit the road in an effort to bring it to a standstill). Instead, deciding not to exercise the PIT maneuver, Deputy Scott pushed the rear bumper of the fleeing vehicle, resulting in the driver (Harris) losing control of the car, jumping an embankment, overturning and crashing – whereby Harris became a quadriplegic.

Harris filed suit asserting that Scott violated his Fourth Amendment rights during the pursuit by using excessive force. After rulings in the lower courts denied Scott’s summary judgment motion on a qualified immunity claim, the matter went before the Supreme Court where, in an 8-1 ruling, they reversed and held that Scott’s effort to end the chase by forcing Harris off the road was justifiable and reasonable, and that Scott was entitled to immunity.

With a quadriplegic plaintiff looking for relief from the judicial system, how is that the Supreme Court found in Defendant Scott’s favor? In a rare and uncommon move for the Supreme Court, they accepted the presentation of video evidence of the chase, the main contributing factor that influenced the court’s decision. Writing for the Court, Justice Scalia concluded, “It is clear from the videotape (Harris) posed an actual and imminent threat to the lives of any pedestrians who might have been present, to other civilian motorists, and to the officers involved in the chase,” thus contradicting Harris’ version of the facts.

In future cases where video evidence is introduced, litigants will be able to cite Scott v. Harris that a court, not a jury, is competent to decide issues usually left to the jury to determine, particularly where video evidence contradicts the nonmovant’s account of the facts.
While security footage can be used to support or refute criminal behaviors, or aid in civil cases, it has also proven valuable in uncovering police corruption and/or ineptness, and in fact, may be the best way to circumvent police lies and collusion.

In 2004, during the Republican National Convention in New York City, a massive number of protesters participated in a broad range of activities, resulting in over 1800 arrests, a record number for any political convention in the U.S. Most of those arrested were carrying out lawful and peaceful actions, yet the NYPD claimed disorderly conduct and fabricated a number of the charges. Video evidence, contradicting the assertions of the police, and much of it provided by private parties, proved the innocence of hundreds of people, with over 400 of the cases dropped.
In another incident last summer, near the Philadelphia airport, four friends made a 3:00 a.m. stop in a convenience store shortly after being involved in a minor fender-bender with their Mazda. The driver of the other vehicle, the son of a police officer, rear-ended the Mazda with his Buick, then left the scene after a purported exchange between the parties.
The Buick’s driver located his father, on duty that night, and the two set out to locate the Mazda, spotted in the store’s parking lot.

Moments after entering the store, 20-year-old Agnes Lawless was standing at the counter when Officer Lopez, father to the other driver, grabbed Lawless from behind and violently pushed her, striking her with his left hand and shoving and striking his gun in her face with his right hand. In a frantic struggle to defend herself, Lawless was arrested and charged with assaulting the officer.

Lawless and her friends filed complaints with the police department’s Internal Affairs division, but in many cases like this it’s the defendant’s word against that of the police…except when there’s surveillance video to prove one’s innocence. The case against Lawless was dropped after video footage from the store’s four security cameras were examined.

In some instances when viewing video evidence, such as with the Lawless incident, the truth is blatantly clear-cut, by even the untrained observer. But in many cases, the proof often falls into gray areas easily argued between opposing parties. When a video forensic expert’s observations, analyses and opinion are based on his own perceptions, experience and expertise, especially without a governing of the profession or widespread acceptance of the science, it’s easy to see why video forensics is sometimes discounted.

Yet, in a world laden with video technology, and with video surveillance systems in nearly every public environment you can imagine, the task of interpreting what is seen on video, including authenticating and clarifying the images, is not within the realm of the legal profession. When the “videotape” is rewound, it is best left to the experts who can help the court better understand the technology and circumstances as they relate to each incident. That is, unless you’re on the side of the fence that thinks video forensics is a bunch of bunk…er, junk. Ultimately, however, in this author’s opinion, especially given the amount of forensic video evidence surfacing in the courts today, the science of video forensics will soon earn the respect of all legal personnel.

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Video Forensic Expert

Video Forensic Expert

There are many activities of a Video Forensic Expert that help the legal system better understand the truth behind video evidence and court room exhibits.

A Video Forensic Expert helps criminal justice personnel to understand the power, potential, accuracy and inaccuracy of closed circuit television systems (also known as video security systems), police car video footage which often becomes evidence to determine probable cause to understand the truth of an investigation, crime or traffic stop.

A Video Forensic Expert reviews the relevant facts about how a video surveillance system operates in relationship to the video evidence being presented.

The Video Forensic Expert then communicates and interprets the circumstances surrounding those events in the court room as it relates to the evidence or exhibit being presented in an expert witness capacity.

The Video Forensic Expert also helps communicate the difference between analogue and digital video closed circuit television systems as well as each format strength and weakness. Helping courts with litigation that includes video evidence, understand how to handle video evidence should it become necessary and how to preserve the chain of custody for digital and analogue video forensic evidence is standard operating procedure for any Video Forensic Expert.

Closed circuit television and other video recording security systems is a visual assessment tool. Visual Assessment means having proper identifiable or descriptive information during or after an incident or accident.

Visit: http://digitalvideoforensics.blogspot.com/2009/11/video-authentication.html for more information on Closed Circuit Television Systems.

Personal Identification is another activity that a Video Forensic Expert often assists with. Video is a solution to courts for reexamining a set of circumstances surrounding a crime because it has the ability to provide the viewer a tool to review a sequence of events, beyond a shadow of a doubt. This does not reflect human identification, but rather, the ability to identify specific information or objects within a video image.


Clarification
Often a Video Forensic Expert must provide clarification services to help laypersons better view video footage. Part of this clarification process is done in a video software program. Other times it may become necessary for a Video Forensic Expert to export a frame or several frames for the video evidence and import into another software program to further clarify an image for identification purposes.

Because of the need for accuracy, it is also the duty of a Video Forensic Expert to examine time-lapse video from closed circuit television systems that may exclude important crime scene characteristics.

For example, if using a digital recorder or DVR, with a low image per second frame rate setting may not capture some important images on the video recorder. The lower frame rate setting is desired by many digital CCTV system users to reduce storage requirements of surveillance video on hard drives.

On the Primeau Productions You Tube page, there are video examples of this frame rate scenario.

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Improper Use of Video Forensic Evidence
In law enforcement, video recording systems are installed in most police cruisers and help bring accidents, drunk driving and other traffic stop situations and crimes into the court room to be reviewed by lawyers, judges and juries to aid with a more positive and accurate legal outcome.
Law enforcement uses video to exhibit probable cause.

Video Forensic Experts help courts understand video evidence and video evidence admissibility. Often time’s video evidence is improperly used and a Video Forensic Expert assists the court by clarifying details that are not easily understood by laypersons.

An experienced Video Forensic Expert is good at breaking down technical language to a level laypersons can understand so they can make better decisions about the video evidence being presented.

Forensic Questions about Video Evidence
• What do we know about this recording to be true (within a reasonable degree of professional certainty)?
• On what type of equipment was the video recording made?
• Is the original recording of the video available for examination?
• Is the original recording equipment that made the tape also available for examination?

Video Anomalies
The Video Forensic Expert also looks for anomalies in a video recording when authenticating a video recording about to be entered into litigation as evidence or an exhibit.

Anomalies are abnormalities, deviations or “breaks” in the recording process as evidenced on the physical tape or digital video file. These aberrations can impact the legitimacy of a video (digital or analogue) as a piece of legal evidence.

Another form of anomaly as of lately is lack of video footage presented.
A Video Forensic Expert is also responsible in determining if all the relevant video footage is present and complete before the video evidence is used in court. Often times a party engaged in litigation will enter incomplete video evidence in an attempt to alter the relevant facts similarly to altering or modifying the video evidence by editing or other tampering. This is another form of anomaly that a Video Forensic Expert can help identify.

Authentication
Video authentication is an intricate process requiring extensive training, experience and sophisticated tools and equipment. Add ever-changing technological advances and increased use of recording devices by businesses and the general public – and you begin to glimpse the expertise needed by a Video Forensic Expert.


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Video Forensic Expert

Video Authentication

FORENSICS: VIDEO AUTHENTICATION PROCESS

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http://www.primeauforensics.com

In audio/visual forensics studies and application, video authentication is an intricate process requiring extensive training, experience and sophisticated tools and equipment. Add ever-changing technological advances and increased use of recording devices by businesses and the general public – and you begin to glimpse the expertise needed by today’s AV forensics professionals.

This post provides an overview of the process of authenticating a digital video file and videotape for purposes of verifying it as legal evidence. Should you need the services of a forensics expert, Ed Primeau has been a practitioner in this scientific field since 1984 and is a certified digital video forensic expert.

Recording over tapes is a common practice with consumers. It’s also quite common with security camera/surveillance tapes. Repeated over-recording of surveillance tapes is pretty much the norm since the use of new, blank tapes for every recording use would be costly, especially if security cameras are on 24/7. As a result of reusing tapes, videotapes being considered for use as evidence in court must often be examined for authenticity and recording integrity by AV forensics professionals.

The first step in the authentication process for an analogue video tape is to make a copy on the VCR used to create the original evidence. This is called making an exemplar.

VCRs actually have an identity, much like humans do. With people, we identify human characteristics like eye color, hair color, weight, body size/type, DNA, fingerprints. VCRs also have record “signatures” which forensics experts need to examine. Essentially, these identifying signatures or recording characteristics are: stop, start, record, record interruptions and other indications discovered on the tape’s audio tracks.

With video recorders, we identify signature characteristics in several ways. First, there are two distinct audio tracks generated on most videotapes that have replicated (or recorded) images existing on tape formats, such as VHS tape. The two tracks are: (1) Linear and (2) Non-linear. Audio tracks provide forensics experts with much information – as does the video control track.

We begin documenting the identity of the (alleged) recording device or VCR by recording a fresh video test pattern – via an NTSC test pattern generator – and a series of audio tones generated by an industry-standard tone generator. These are recorded onto a virgin (blank) tape.

Hertz frequencies are also examined. Hertz, or Hz, is an audio frequency measurement, similar to decibels (db) measuring audio volume intensity. HZ frequencies examined in forensics generally include 250 Hz, 1000 Hz, 3000 Hz and 8000 Hz. Reading and comparing these frequencies is achieved by use of a computer spectrum analyzer. (Primeau Productions uses an industry-standard analyzer made by made by Sound Forge.)

A comparison analysis is conducted on the exemplar and on the original evidence tape. Note that even if the videotape being examined under forensics scrutiny has no picture, the audio tracks can still be examined for evidence, along with the video’s control track.

Once we have an exemplar made on the same equipment on which the evidence was made, it’s time to address further comparisons.

Video recording signatures (think of them as similar to human signatures) are examined. Stop/start record signatures are studied; record-interrupt distances are measured physically. Developing” the tape itself by applying Krylon magnetic tape developing fluid exhibits the nature of the signature or anomolie. This fluid is amazingly effective in revealing the true recording signature – very similar to how fingerprint dusting powder reveals a person’s fingerprints.

After viewing the entire videotape using the “fast forward” mode, where ever a record interrupt is visually observed, the tape is stopped as near as possible to the exact interruption spot. The tape is disengaged (ejected) and physical exam of the tape commences. Krylon magnetic tape developing fluid is applied to the tape itself to reveal stops in the tape. (See exhibit 1, attached, which is a digital snapshot of a VHS tape “developed” with the magnetic tape developing fluid.

Notice the vertical line straight up the tape. This is where the recording stops.

It is apparent that, due to the region to the right of the vertical line, this tape has been re-recorded over a previous program. The distance between the stop signature and the curved restart signature to the right of the dark region is the gap in the engage mechanism. The curved program continuing would be another straight line of the tape, indicating that recording was stopped then restarted.

When a new videotape is inserted into a recorder, the tape is threaded into the engage mechanism. This places the tape against the recording head; this action actually pulls the tape out of the shell and threads it across the tape head. This process can be recreated if it becomes necessary.

If a recording is stopped, the engage mechanism disengages. If the recording is continued, and the tape is not shuttled, the tape is re-engaged and the recording continues. However, some physical “glitch” will be evident in both the TV monitor image and in the physical examination of the developed magnetic tape. In addition, evidence of this interrupt is often obvious (and substantiated) by examining the control track.

Since Exhibit 1 continues with a curved line, this is an indication that the tape was stopped and the time taken for the machine to disengage and stop recording. This is obvious due to the blank space between the vertical line and the curved record disengage which follows.

After the first identified record interrupt is examined and documented, physical study of the tape continues by repeating the process in search for any other interrupts – re-engaging the VHS tape into fast-forward tracking mode until another glitch is noticed. Naturally, the entire above process of developing and observing is again repeated for each instance of noted interruption.

Next, as required by the scientific community and forensics procedures, the exact length of the videotape must be established. While most videotapes have a time/length stamped on the spine, length verification is needed. The length is imprinted on the spine of the plastic shell that houses the physical tape itself – example: 120 or 160 may be imprinted. However, the stated length must be verified by taking a measurement. This is verified using information obtained using the hours/minutes/seconds display on a well-maintained, professional videotape recorder.

To do this, the tape is completely rewound to the beginning and the tape counter is reset as the start point. Then, fast-forwarding the tape to the end, the digital counter’s reading at the tape’s end point is observed and noted. Now, if the reading on the videotape display count is less than the indicated stamped length, this can be an indication that the tape has been tampered with. If the time is more than what is indicated on the spine, that’s acceptable. (Most tapes are loaded “long” from the factory; a manufacturer’s 120 minute-length tape may actually be 121¼ minutes, or thereabouts.)

Then, using a cross pulse monitor, any glitches discovered on the tape are measured and checked considering other conditions that exist on the tape (i.e., the tape’s “fingerprints.”)

The cross pulse monitor measures the glitches – different electrical and magnetic fields on the videotape – similar to how an EKG records and measures electronic signals from a human heart. Even if there is no video image on the tape, tape signatures can still be revealed during this monitoring test as long as the tape has been recorded on at some point.

Glitches are also examined using a frame-accurate professional tape deck. Since NTSC video (the standard in the U.S.) is 29.95 frames per second, one can observe individual video frames using the frame-accurate machine. If a tape has been re-recorded, a stop signature will be frame accurate (i.e., one frame has an image and the next frame does not).

On the frame-accurate deck, one will notice video frame deterioration over a series of several frames after the stop occurs, the deterioration appearing as “snow,” or video noise, on the screen/monitor. Basically, the image kind of fades out; then we can observe a gradual fade back-in from “snow” to the resumed image that was captured on the tape during recording. (Hence, Exhibit 1’s curved restart of previous recorded program.)

If a recording is stopped, and the tape was disengaged from the tape head then re-recorded, we would notice something very different. Physical examination using the magnetic tape developing fluid would reveal a straight vertical line, indicating the stop, and a straight vertical line indicating the re-start of the recording. A professional, frame-accurate video deck would reveal frame-accurate stop/start with no fade-in. Many of these tests can be conducted or recreated using a professional frame-accurate video deck.

If any frames need to be examined further, the video sequence is loaded into a computer using a professional video capture card, manufactured by Targa. NOTE: Targa is a professional-brand capture card. Off-market and consumer video capture cards are not of the highest resolution; they should not be used when forensics/scientific reliability is at stake.

Once the footage has been loaded into the computer, using the Adobe Premiere program, we can further examine the frame sequence and print out any exhibits as necessary.

Note, also, that videotapes can be physically cut and spliced. Thus, glitches detected during the process will also prompt the forensics expert to examine a tape for physical splicing (as opposed to electronic splicing or edits resulting from re-recording over tape images). A splice repair is generally made with an adhesive-style clear tape on the videotape. To the untrained eye, these could appear to be several scene changes. To the trained eye, these indicate that the tape has been recorded on previously or is possibly a physical splice to be examined.

Note, too, that it’s a good idea to read these and other stop/start signatures using an oscilloscope, as well as physically using Krylon fluid to confirm record-interrupt theories.

Next, all test results must be compared from the original evidence tape to the exemplar test results to determine if both tapes were made on the same equipment. The scientific community requires that forensics experts document all test steps and procedures, as well as equipment type, as in the authentication process in order to substantiate conclusions arrived at.

The digital video examination process uses similar equipment but involves a much different testing process. Digital video files are examined and authenticated based on their chain of custody. The equipment used to create the digital video files must be understood and examined as well. Compression, image rate and codes are also studied as part of this investigative process.

Video Forensic Analysis and Tips

Today, evidence from video recordings plays an increasingly significant role in the criminal justice process. It’s an example of the newer forms of evidence that law enforcement officials take into consideration when presenting facts in court cases.

Video footage from in-car mounted cameras in police cars, security cameras used for businesses, institutions, stores, etc. – plus footage from private citizens – is often surfacing as evidence in legal situations. Perhaps you have convinced your department head or company to install a surveillance system to monitor security situations and possibly detect instances of crime. And perhaps the camera/recorder has captured footage that may be key to a convicting a perpetrator. Unfortunately, during the “discovery” stage of the case, the defendant’s attorney states that something happened to the video recording; there is a glitch. He announces that a forensics expert is now on his defense team to prove that your video has been falsified and/or inadmissible.

This brief article covers video forensic examination tips that may keep your recordings glitch-free. If you are involved in video recordings that can be used for legal evidence, this article may save you from having your evidence challenged in court.

As a Video Forensic Expert, I’m often hired by law enforcement officials, attorneys and corporations to report on the methodology used in videos cited as legal evidence. As part of my work, I review many resources, like police chase footage, hidden-camera coverage from workplaces, retail store surveillance footage, and so on. The question I’m most often asked is to respond to is: “Was this video recording edited or altered in any way?”

To respond to this, forensic experts must gather scientific clues to answer the following questions:

• What do we know about this recording to be true (within a reasonable degree of professional certainty)?
• On what type of equipment was the video recording made?
• Is the original recording of the video available for examination?
• Is the original recording equipment that made the tape also available for examination?

While extensive technology is certainly involved in the video recording process, and this article cannot begin to address it fully, here are theories/procedures regarding examination which provide an overview of how forensic experts may need to examine and identify video anomalies.

Anomalies are abnormalities, deviations or “breaks” in the recording process as evidenced on the physical tape or digital video file. These aberrations can impact the legitimacy of a video (digital or analogue) as a piece of legal evidence.

Digital Video
When a videotape recorder or digital video recorder (DVR)/video camera records to videotape or DVR, the recording process creates a very structured format of code and information that is embedded on the tape or hard drive to create pictures and sound and signals. (Note, all videotape, except ¾” format video, travels from the left spool to the right spool when the machine is in the “Record,” “Playback” or “Fast Forward” modes. DVR recordings store video signal on hard drives using proprietary codecs or code and compression).

Digital video requires a different forensic process than analogue. Instead of recording the video image on tape, digital video is recorded on computer hard drives or digital video recorders (DVR).

Video systems that record digital video have several variable settings like frame rate and recycle time. If you look at the video below, you will better understand the importance of frame rate and forensic examination. Some officials and owners of digital video systems choose a lower frame rate to save on hard drive storage space. This makes it difficult for the forensic examiner to authenticate and identify events in question on the video recording. It is more efficient and effective for closed circuit television (CCTV) owners or purchase additional hard drive storage instead of choose a low digital video frame rate.

There are also several manufactures of digital video CCTV systems making it necessary for the video forensic expert to review operators and installation manuals for each system. I have been certified by the Pelco Global Institure in digital video and understand the details of digital video systems and the processes necessary to investigate digital video surveillance footage.








Analogue Video
On analogue tape, at the bottom of the tape (running just parallel to the tape edge) is the control track, or recording signature. Just above the control track is the composite picture and audio signal. On hi-fi VHS video recorders, above the composite signal, there are the hi-fi tracks. These are the physical areas of the recorded tape that forensic experts look at to determine if glitches – or anomalies, as they are professionally termed – exist.

There are two types of anomalies: non-destructive and destructive. A non-destructive anomaly is any deviation from the normal events one would expect to see and hear when viewing a videotape. In other words, a non-destructive anomaly or glitch in the tape could be an edit, an indication of a record interrupt or an over-record (recording over a previously recorded tape or segment of the tape).

When examining a tape for anomalies, the forensic expert must take all things into consideration. For this reason, it’s strongly recommended that the examination start by determining the origin of the recording device. If the machine that made the recording is available, a test recording – or exemplar – should be made using blank, unrecorded (virgin) tape. The goal here is to gather information on the alleged machine signatures from the original recording device used – that is, signals from the control track and the stop and start signatures. This is done for comparison purposes and to identify facts that may exist about the anomaly.

Next the tape being examined – i.e., the evidence or the alleged video containing the in-question anomaly – is viewed in “Play” or “Fast Forward” mode to determine the number of deviations or anomalies. Each deviation is carefully noted and examined using test equipment that helps to determine the characteristic of the anomaly. Much like the medical profession uses testing to research and document the reason for an illness, diagnostic tests are also necessary for forensics professionals; testing will eliminate certain factors so that real facts can be isolated to conclude, to a reasonable degree of professional certainty, the source or cause of the anomaly.

Many times it is necessary to physically examine the tape at the actual spot where the anomaly exists. An expert will physically examine the videotape itself to accomplish this, applying a special, non-destructive liquid to the tape which then develops the digital information so it can be reviewed. (This is much like how a photograph is developed, applying developer chemicals to the film.) Once the tape is “developed,” the expert can continue with the physical examination processes.

For a jaunt back in history – yes, in the “olden” days when I began my career – video recording tape was not yet in plastic shells but rather on spools, making it fairly easy to physically review the tape; but it was also quite easy to damage the tape’s edges since the tape was a good deal more exposed to mishandling. Videotape edge damage is considered a “destructive anomaly.” This damage can be in the form of a crease, tape crinkle, the result of a liquid spilled on the tape, etc. Of course, this can still occur with today’s videotape, even in the protective shell or tape housing, but not as easily.

Also, back then, videotape was comparatively more expensive than it is now. Thus, videotape was quite often recycled and recorded over for economy’s sake. As you might imagine, anomalies were fairly prevalent in those years. In one respect, this was good for my skills development as a forensics expert since I had the opportunity to experience dozens and dozens of destructive anomaly situations during the late ‘70s, for instance. This permitted me to gain great insight into their cause and nature.

When videotape started to be enclosed in cassette-styled plastic housings as VCRs gained in popularity, it became a bit more difficult to physically examine tapes for anomalies. So the scientific community evolved accordingly and developed new ways of testing.

Once you understand the science of how video recording works, how recordings and devices can be distinguished from each other, you’ll have a better understanding of how to go about identifying anomalies. I encourage you to read up on today’s video technology to advance your knowledge.
(You may also wish to refer to another article, “Forensics: Video Authentication Process,” included on this website.) Meantime, for simple practice in identifying anomalies, try creating your own:

Take a tape that has been previously recorded over. Fast forward the tape to about 10 minutes in and record something new, getting about 30-40 seconds’ worth. Rewind the tape and review your “over-record” characteristics. Take note of how the over-record starts and how it ends. These “in and out” points are characteristic of the equipment on which you recorded the program.

Of course there are many other forensic aspects in the study of anomalies –examination of stop/start record “signatures,” record-interrupt distances on the tape, study of the audio and video tracks, control track examination, application of magnetic tape developing fluid to further detect anomaly conditions – to name key areas.

But getting back to what’s most likely your interest in uncovering reasons for an anomaly, this works down to two essential questions: Did it occur as a result of wishing to intentionally cover up something? How do we know it wasn’t an honest mistake? And finally: Can we recover the images and sounds of the previously recorded material?

The answer is no. Once original material has been recorded over, it’s gone forever. But, as mentioned, the machine control track, audio tracks, etc., can provide recording “signatures” that exist on the physical tape; these may contain the clues toward determining others certain “truths” about the over-record. Our article on “Video Authentication Process” provides added information on these points.

When dealing with a video recording device and tapes that may be needed to substantiate legal situations: Make sure your equipment is cleaned and well-maintained and do not use videotape that has been recorded on previously. Use a new tape.

With the main investment already made in video equipment, the slight cost and effort to maintain that equipment – and the nominal cost of fresh tape stock for all recordings – is well spent. Having a clear recording on new tape stock (which avoids pre-existent anomalies that would exist on recycled tape) is an inexpensive way to better ensure your videotape evidence is solid and will be less apt to be court-challenged for authenticity.

800-647-4281

Closed Circuit TV Video Problems and Solutions

By Edward J Primeau, RI

As a video forensic expert, I have seen almost everything when it comes to Closed Circuit TV. Some of it is very disturbing, but much of it is benign -- from the lady whose ex-husband is stalking her, to the bank that just captured a robbery on video. Understanding CCTV systems has become part of the video forensic examiner’s job because a majority of video evidence is made on CCTV systems. In the following article, I will give you my tips, from a forensic perspective, on CCTV.

Imagine this. You are the proprietor of a convenience store. Last night at 11:06, you rang up a customer’s Snickers bar and a Jumbo Slurpee. The customer reached in his pocket, pulled out a gun, and put it to your head, demanding all the cash in the register. Terrified for your life, you gave him the money. Luckily you had a CCTV system and turned the tape over to the police. The police sent it to a forensic expert because all you could see on the tape was a dark silhouette of the criminal. Unfortunately, the robber’s face and features were unidentifiable.

Although CCTV systems can prove to be beneficial for many reasons, they can be useless without some well thought out considerations. My hope is that the law enforcement and legal community will read this article and pass on the information to the businesses in their community.

CCTV is a network of cameras hooked to a monitoring system so that various locations or angles can be viewed and/or recorded. It does differ from broadcast television in that CCTV cameras are not openly broadcast through the airwaves. However, some CCTV systems have point-to-point transmissions (wireless cameras) that could be intercepted by someone with the equipment and knowledge to intercept that signal.

The benefits outweigh the drawbacks for implementing CCTV systems for several reasons. Think of how CCTV systems have helped our traffic problems. Having cameras all over our roads and highways allows accidents and traffic jams to be discovered sooner so traffic can be rerouted. In banks, casinos, airports, shopping centers, businesses and military bases, CCTV systems can prove beneficial against crime.

There are some drawbacks that can really cause problems with CCTV systems.

These systems can be expensive. They can be considered an invasion of privacy. Also, a system can fail because of a bad or over-recycled tape, and the crime will not be recorded.”

For some strange reason, businesses who still use VHS tape to record their surveillance often insist in recycling their videos beyond a logical limit. Then, when the expert needs to lift an image off for identification, fuzzy, blurry photos are produced.

In the convenience store example above, the camera was in the wrong position. A light was installed in a recently added display that was not in the store when the CCTV system was installed. Nobody ever updated the CCTV system or performed maintenance to discover the problem.

The purpose of this article is to share some of my experiences with CCTV footage and provide some tips from a forensic expert’s point of view, sound advice to avoid costly mistakes and expensive forensic restoration.

Number one: Plan your CCTV system layout in advance. Do not put in a CCTV system without planning for your potential crime circumstances. What crimes could be executed under the watchful eyes of your CCTV system? You can call this crisis management. Draw a diagram of this activity, and use it as your blue print for locating your camera positions. If you own a business that has a back lot to cover, don’t just mount a camera to the back of your building, thinking it will do the job. Consider what you have to protect, the value of these items, and the various ways a criminal could get at them. Then, place the camera (s) to cover all potential activity. Consider multiple cameras because, in the long run, it will save you money.

Because so many systems were not planned thoroughly in advance, the majority of my forensic cases involve video restoration and clarification. So much of this can be avoided.

Number two: Use a digital video recorder and record direct to hard drive. If at all possible, do not use VHS . There are some great companies like Focus Micro and Crest Electronics who specialize in DVR CCTV systems, maintenance of the system, and training your staff to use them properly. They offer some excellent products and CCTV systems, and will even help you plan your system layout.

Number three: Make sure to account for lighting conditions as well as sun positions.

About one out of ten of my cases require comparison of a frame of evidence from darkly lit video with an exemplar frame or photo. Make sure there is light where your camera is located. If necessary, hire an electrician to put in a light or two near your camera, especially if the potential crimes that warrant the installation of your CCTV system can occur at night. Duh! I can hear the installer now, “Sure looked good in daylight”!

In addition, consider sun positions all year long. Remember sixth grade science class? The sun changes positions with the seasons. Bright sun facing the camera will cause the iris in the camera to close (in automatic position), causing the image of the perpetrator to darken. Try this with your home camera. Take a video of your friends with the sun behind them instead of behind you. The friends will appear dark because of the camera’s lenses adjusting for the high light level.

Number four: Plan camera positions for all possible situations. I have heard it said that if you want to rob a bank, wear a baseball cap. Why is it that CCTV installers put the cameras in high positions that will never show a criminal’s face?

Number five: Keep your camera clean. Car dealerships wash their windows and cars weekly if not more often. Why don’t they wash their cameras? Think about it. Many outdoor cameras are somewhat protected from the elements, but after awhile, dirt will still gather on the surface of the camera lenses.

A solution of Shaklee basic H or white vinegar in hot water will clean them nicely without scratching or clouding the lenses or protective housing. Harsh cleaning chemicals can scratch or cloud the glass, especially on Plexiglas camera housings.

Number six: Do not use wireless cameras. If at all possible, run cable and go wired for your entire network. Wireless cameras are unreliable, especially in storms.

Almost all maintenance can be performed by you or done very reasonably by a professional. Avoid costly mistakes and tragedy by keeping your system maintained and updated. (Use Google to seek a professional in your area who can help with your circumstances.)

Ed Primeau is a video forensic expert, Author, professional speaker and business owner in Rochester Hills Michigan. He is the author of two books, “The Art of Production” and “The Video Revolution”

email Ed@PrimeauProductions.com 

800-647-4281