A Video Forensic Expert Looks at the VIEVU Wearable Camera

Vievu LE2

Giving the VIEVU LE2 my highest recommendation is easy. It is, without a doubt, the best wearable personal surveillance camera I have encountered in 25+ years as a video forensics investigator. Developed by police for police, this unit gets it all right; size, shape, weight, operation, picture quality, sound quality, date & time stamp, capacity, convenient downloading, storage, management, and digital signature security.


Advantages to Video Recordings

Obtaining a video recording of events at a traffic stop, pedestrian stop, crime scene, or call for assistance is most important. A video that captures the point of view of the officer is invaluable as a record of all an officer’s activities. Not only does it protect officers and citizens, but it holds all parties accountable. Videos are also introduced as an evidentiary recording in a court of law. Put simply, having some kind of recording is always better than having no recording at all. I would choose the VIEVU over a fixed vehicle cam or handheld camcorder every time. Unobtrusive, reliable, and easy to operate, I look forward to the time when every police officer in the country wears a VIEVU.


Challenges of Video Recordings as an Expert Witness

Testifying as an expert witness, I’m most often challenged by the opposition attorneys in the chain of custody and findings. Years of experience lend confidence in my analysis of the evidentiary video recording. Issues arising from authenticity and chain of custody are more challenging.

I am not always the person who retrieves the recording. That means that I must rely upon the record-keeping of others to establish an unbroken chain of custody, a paper or digital trail that accounts for every individual who had the recording in his or her possession up until I receive it and thereafter.


VIEVU Software

VIEVU solves this problem with its VERIPATROL VidLock Security Suite. The software utilizes a FIPS 140-2 (Federal Information Processing Standard) compliant digital signature, which guarantees the recording’s authenticity and integrity. This cryptographic standard ensures the authorship of the recording and that it remains unedited.

The LE2 records at 640 x 480, standard definition, but with an important difference. Under forensic examination, most standard definition video is actually 640 x 240, because each frame of video is made up of two fields. With standard, interlaced scanning, the odd vertical lines record before the even lines, which produces a visible lag when viewing the full-frame. The LE2 employs progressive scanning, in which all 480 lines record simultaneously, producing superior vertical resolution. 30 ips (Images Per Second) is always preferable to 30 fps (Frames Per Second).

This makes my job easier when performing forensic video analysis. Digital footage captured at 640 x 480p strikes a good balance between file size and resolution. Since most conversations occur at a distance of six feet or less, officers wearing a VIEVU record an ideal, detailed field of view, thanks to the unit’s well-chosen, 71 wide-angle lens.


Our Recommendation

I use the LE2 to document evidence retrieval in the field. The camera works perfectly, providing a time-stamped video record of the DVR I’m working on and its location. And I’m looking forward to receiving the company’s newest upgrade, the hi-def LE3.

For more info on VIEVU and their products, check out CEO Ed Primeau’s interview with VIEVU CEO Steve Ward here!

Video Evidence Recovery for Video Enhancement

Video Evidence RecoveryThe importance of proper video evidence recovery is clear to those of us involved in forensic video enhancement. During the process of video evidence recovery, we make sure the highest quality video recording is properly saved for court use. Video forensic experts receive extensive training in video evidence recovery.

As a forensic expert, I have worked on many cases involving digital video recordings admitted into evidence in court. Much of our work with these recordings involves video enhancement, which allows the trier of fact to better see events as they occurred. Often times, video surveillance systems or smartphones record the digital evidence in question. We properly remove recordings from both mobile and stationary surveillance systems for forensic enhancement.

Stationary surveillance systems record video at locations such as convenience stores, banks, and other businesses or institutions. Buses, trains and other types of public transportation utilize mobile surveillance systems.


Evidence Recovery Importance

There are three main factors we would like to mention regarding the reason for proper evidence recovery. First, when we retrieve recorded video evidence, we create a video recording of our process. This establishes an indisputable chain of custody. It also demonstrates for those who were not present the process and procedure we used. We take special precautions during the retrieval process to make sure we leave with at least one version of the recording. Additionally, we leave with the recorded video evidence for future forensic enhancement and authentication as necessary.

We retrieve the recording so as to minimize any degradation of quality. When a lawsuit depends on the analysis of a surveillance video, it is important not to leave evidence retrieval to an untrained security guard.

We research the operator’s manual and connect with tech support from the surveillance company before traveling to perform evidence recovery. While on site, we also examine the administrative log and determine additional forensic information for the chain of custody.


Video Evidence Recovery Best Practices

An excellent manual for retrieval of electronic evidence developed jointly by the federal government’s inter-agency Technical Support Working Group, the FBI Forensic Audio, Video, and Image Analysis Unit, and law enforcement agencies from around the world. Entitled Best Practices for the Retrieval of Video Evidence from Digital CCTV Systems, it contains an authoritative (if somewhat dated) overview of the topic and covers many of the protocols we have adopted at Primeau Forensics.

Before digital audio and video recorders, retrieving a tape-based analogue recording was fairly straightforward. Recordings were made to tape cassettes, which were stored in climate-controlled conditions. Evidence retrieval was as simple as picking up the original cassette recording. Digital video recorders (DVRs), however, do not record to easily portable cassettes. Rather, they record to the kind of hard disk drives found in computers. These internal hard drives are not portable, making evidence retrieval more difficult. Whether we take the DVR or its internal drive with me or make a lossless copy of its contents, I always follow anti-static procedures and carry all media in specially shielded cases.


Proprietary vs Open Source Video

All surveillance and standard digital video uses a specific compression/decompression scheme or codec to record. The compressed file’s storage structure determines its format. It is not uncommon for surveillance DVRs to use proprietary formats, allowing playback only through the original recording DVR. Some DVRs can re-compress the original proprietary format file, trans-coding it into a non-proprietary format for easy playback. However, these more accessible files often contain lower quality video and audio. When we retrieve these digital video files, we study the DVR’s operating manual to find the best way to make a high quality copy that retains all data and metadata. By minimizing or eliminating the degradation that can accompany translating the file from one format to another, we ensure that our lab analysis is based on the best video recording available.

A DVD is NOT an Original Video

DVD EvidenceMore often than not, a DVD is not an original video.

Many law enforcement organizations create DVD copies for defendants because they are much easier to play than native digital video formats. This can be confusing so allow me to further explain.

Over the last 30 years as a practicing audio/video forensic expert, I have experienced many digital file formats, as well as analog tape formats, used in litigation. Usually, they are able to successfully serve a purpose by showing the facts as they occurred. These videos help bring the scene of the crime into the courtroom so the Trier of Fact and the jury can make decisions more accurately. People alter video and eliminate sections they do not want the court to see.

This is why as a video forensic expert, I am asked to examine and authenticate video evidence when one of the parties in the litigation disagrees with the contents of the video. When the video evidence is presented on a DVD as a VOB burn, it is nearly impossible for me to authenticate because the metadata has been stripped. When a digital video is created, the metadata in the digital video file has information about the equipment that made the digital video file, the date and time the digital video was recorded and most importantly, a footprint of any video editing software that was used before that video was admitted into evidence. All of this metadata information is stripped from the digital video recording if the video has been burned to a DVD.

Part of my job is to investigate the history of the video in evidence and help attorneys and prosecutors obtain originals or better understand the video evidence before any due process begins. One of the biggest problems I find is that most of the video entered into evidence is on a DVD and is not original. When either of the litigators question the contents of a video, they ask for my help to determine if any editing or alteration has occurred. I always encourage prosecutors and lawyers to maintain the original video evidence in the recorder that created it because that way, a full forensic investigation is easily executed.

Once that original video is deleted, it becomes much more difficult to investigate forensically. In some cases, a properly made copy of the original evidence will include the important metadata necessary for the authentication process. Leaving the digital video file in its native format is much better than converting the video format to a DVD VOB file through the burning process.

Video as Evidence – The Importance of Video Authentication

video authenticationWhy is video authentication important? As a video forensic expert, I often find that videos submitted into litigation are not original as the person admitting has stated. Instead, they are copies that have been altered to only contain the events they want the trier of fact to see. From a forensic perspective, this is not fair because the original video will contain all the events as they actually occurred. Some of the events that were omitted have relevance to criminal or civil litigation.

Last week, I testified in court in a video authentication case. The report that I wrote for the case was admitted into evidence. My report revealed that a video had been altered and was not an original.

I testified that my report revealed the scientific findings and my conclusion that the video recording was altered and not an original. Both conclusions were scientific and if I conducted the same test 1000 times over, I would arrive with the same conclusions. If any other forensic expert were to conduct the testing that I had documented in my work product and report, they would arrive at the same conclusion as well.

Lately, I authenticate all forms of video. Store CCTV, cell phone video, and tablet video. We live in a video world! Anywhere you go out in public you are more than likely being video recorded. If you are riding a city bus, you are more than likely being video recorded. Some civilians have installed mobile CCTV systems in their cars just in case they need to defend themselves or catch a crime in progress.

The police originally installed cruiser video recording systems to first protect themselves and to also protect the citizens from prejudice. Cruiser video holds the police accountable by recording probable cause for traffic stops

Forensic experts have many tools to determine scientifically if a video is first, original and second if a video has been altered. It is especially difficult with digital video to determine how a video was edited if it does not purport to contain the information or events either litigator states that it should contain. This is where forensic investigation becomes the only way to determine the video evidence authenticity.

If you believe a video has been edited, here are a couple of things you can do personally to determine if your video may have been edited.

  1. First, determine the file format on your DVD or CD Disc. Insert the disc into your computer, left-click on the drive, and select open. Is the file format VOB or MP4, AVI, MOV? This format is actually the video container.
  2. Next, go back to the file folder, left-click to open, find the video, and right-click on the file. All the way at the drop-down menu is the word properties. Left-click to open and review the MAC information. Modified, accessed and created information will reveal dates. Does the disc/CD created day to read a date that the litigator who submitted the video stated the date created to be?
  3. The length of the video can also be a clue for your preliminary video authentication. Are there any phone records to compare to the length of the video? Does your memory of the series of events match the length of the video and video events?

Of course, there are many more steps a video forensic expert will take in order to determine if your video is genuine and authentic. Even if there is no audio on your video recording, the audio track can also reveal information about the authenticity of your video recording.

Video Enhancement Strategies of a Video Forensic Expert

video enhancementEvery case that requires video enhancement requires the video forensic expert to develop a strategy comprised of a series of steps and forensic software tools. Back when surveillance video was an analog videotape, video enhancement was more difficult. The equipment forensic experts used to conduct video enhancement was entirely hardware-based. Forensic experts did the best they could with what they had to work with.

Today, technology has progressed, making several scientific community-approved software programs available. One thing that causes difficulty during video enhancement is poor camera placement.

Installation of CCTV cameras must be well thought out in advance in order to aide in the forensic investigation, should a crime be committed. In addition, the sun constantly moves throughout the day and affects the surveillance video camera by over and under-exposing the surveillance area.

Outdoor cameras become dirty after a period of time, making video enhancement difficult. Point Tilt Zoom (PTZ) cameras provide much better video surveillance footage because of their ability to move, follow and zoom in on perpetrators more effectively than surface mount cameras. An ounce of prevention is worth a pound of cure. Making sure the surveillance system is properly thought out and installed will make video enhancement more successful than trying to fix problems that could have been avoided.

I do not have to convince you of the value of surveillance video; the number of court cases that have video forensic evidence speaks for themselves. Surveillance video recordings produce very useful high-quality digital video recordings that aide litigators in the courtroom see the events as they originally occurred.

Video enhancement is challenged by one thing: the fact that most security video recordings must be viewed on a proprietary player, a software program that has the ability to interpret the specific manufacturer’s secure code, which maintains the integrity of the video recording, keeps the video secure and reduces the vulnerability of editing. This proprietary player makes it very difficult to alter or edit the surveillance video. Some manufacturers allow the ability to export video files from their surveillance propriety players and others do not. This poses a challenge for the video enhancement expert.

The best bet in any situation that requires video enhancement is to talk to an experienced video forensic expert to learn what is possible and what is not. Video enhancement is misled by what Hollywood produces and often confuses the public as to what is possible and what is not.