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, …Read More
The 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.
More 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 …Read More
Why 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 …Read More
Every 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. …Read More
How can I tell if my video recording has been edited? In order to authenticate video evidence accurately, a trained video forensic expert must perform the testing to ensure the authentication process is done accurately. The expert performs a series of tests on the metadata as well as the visual …Read More
After the bombs exploded at the Boston Marathon, the FBI immediately went to work investigating all available video evidence to begin the video forensic process. Several sources of video evidence were available for FBI forensic examiners, including:
The first camera that FBI investigators began working with to clarify images was from …Read More
It is very obvious that we are vulnerable to attacks with little or no advance warning as exhibited in the recent bombing in Boston during the marathon. There are so far reported 176 casualties; 17 critical and 3 fatalities. Now the daunting task of forensic video investigation must take place.
Part …Read More
In many of the cases I investigate as a video forensic expert, there could have better outcomes. If more thought was put into CCTV surveillance camera placement locations, more CCTV video would be useful in litigation. Here are a few things to keep in mind when deciding where to place …Read More
Traditionally, a chain of custody is established between all parties when handling video forensic evidence. Most of the time, the chain of custody process is easily established and agreed upon when bringing in a forensic expert to authenticate or clarify and enhance the video evidence. This is a blog post …Read More