Uncovering Forensic AV
The fascinating world of forensic AV includes a whole niche of specialists who analyze audio and video recordings using cutting-edge AV technology, revealing clues that help solve investigations.
Thanks to popular primetime shows like CSI and Cold Case, the field of forensic science has enjoyed vigorous growth and wider recognition in recent years. The weekly starring role of forensics on TV has had a ripple effect across several different markets. In the education market, university students who dream of being the next Gil Grissom are flocking to forensic science classes. In law enforcement, officials are finally getting federal and state funding for greater forensic abilities. The AV community is also seeing greater demand for forensic AV services — from local prosecutors to police departments to private citizens.
Perhaps the biggest influence in the forensic AV field is the TV show CSI. Labeled the “CSI effect,” the show's portrayal of forensic science in general — and forensic AV in particular — has pushed the boundaries of reality and fiction. A mere mention of the show fuels a discussion about its impact on actual forensic practitioners like Robert Sanderson, owner of Audio Video Forensic Labs in Poughkeepsie, NY, who explains a scenario that might play out in three minutes on one episode could take significantly more time to solve in the real world. Citing an example of a homicide case he recently worked on, Sanderson received an image of a dark SUV driving behind a victim's car. Looking for trace evidence to rule out the vehicle as belonging to the alleged killer, he worked with two PhDs in Russia for weeks to write the code to deblur the wheel and reveal the depth of the image. In the end, he was able to successfully deblur the alloy wheel design and uncover evidence of an accomplice.
“The CSI factor is a double-edged sword,” warns Kelly Humphrey, forensic video analyst for Forensic Tape Analysis, Inc., Burlington, WI. “The extra awareness is good, but the show has brought on the expectation that high-quality video can be recovered from anything. We as forensic AV experts need to educate our clients —and in some cases juries — that what they see on CSI isn't always real.”
David Mariasy of forensic audio lab Team Audio in Toledo, OH, agrees. “Sometimes people are disappointed with the outcome, even though it's the best outcome that current technology can provide,” he says. “They think that audio should be crystal clear from any source in five minutes — just like on TV.”
The program CSI is certainly entertainment, not reality, says Grant Fredericks, a noted forensic video expert, former police officer, former coordinator of the Vancouver Police Forensic Video Unit in Canada, and current public safety solutions manager for Avid Technology, Tewksbury, MA. “But it does push the envelope of science with its imagination. It's had a positive effect on forensic science in general; I attribute the growth in forensic education on the popularity of the show. And because of the growth in education, there's an interest in government to drive development.”
Forensic work, as portrayed on television, deals with trace evidence, such as a drop of blood or snippet of hair. But in many cases there's also trace AV evidence at a real crime scene, which can range from poor-quality images captured on a consumer-grade surveillance camera across the street to a fuzzy audio recording made by a concealed microcassette recorder. Uncovering that trace AV evidence is up to forensic AV practitioners who enhance, compare, restore, and authenticate the audio or video.
The forensic profession recently made headlines with the London train bombings on July 7, 2005. Enhanced photos of the four suspects taken from subway surveillance video were beamed across the world — a move by law enforcement that helped apprehend the bombers. Even more recently, New York's transit agency announced on Aug. 22, 2005, that it will spend $212 million to improve security on subways by installing 1,000 surveillance cameras along with an array of sensors and software.
As in the mainstream AV world, digital technology has impacted forensic AV as well. In forensic video, the proliferation of digital closed circuit television (CCTV) security and surveillance systems are driving the growth of the market. The cost to own and operate a digital CCTV system is steadily dropping, allowing more businesses and consumers to install such surveillance systems. “The CCTV industry was traditionally produced in analog, but now there's a migration to digital,” Fredericks says. “I would estimate that 80 percent of new installs are digital.”
According to Fredericks, there has been a rise in the number of police agencies over the last several years that have forensic AV capabilities. “Most of the larger police departments have in-house video analysis,” he says. “The private sector has also grown. Over the last several years, the officers who did forensic AV for their police departments are retiring and discovering it a niche opportunity to go into private practice. Meanwhile, production companies see forensic AV as a vertical opportunity.”
Forensic audio is also seeing a move to the digital realm, with some labs seeing as much as 25 percent of incoming material in digital format. Audio recordings are commonly sent as WAV files that can be easily downloaded and emailed to the lab. While differences in compression rates pose a potential problem, current advances in software can usually overcome that difficulty. “The only problem is that the new digital technology isn't that great,” Fredericks adds. “There's still a lot of poor-quality digital video out there. However, even crime scene video is moving to high-definition video.”
Forensic AV is still a small but growing market segment within the AV industry. As such, only a handful of manufacturers have developed or tailored AV products specifically for forensics. “Forensic audio and forensic video are two completely different disciplines, each with its own skill set and process,” Humphrey notes. “In our facility, audio and video labs are separate rooms.”
In forensic video, the most widely used program is the dTective software solution powered by Avid. Based on Avid's video production capabilities, the dTective plug-ins by Ocean Systems are tailored for law enforcement by providing tools that help enhance the presentation of evidence in court like tie-in transcripts, onscreen case notes as meta data, and unique color calibration tools. More than 800 law enforcement agencies are currently using Avid systems with some now purchasing their third or fourth system. Avid has gained additional ground in the forensic video market by providing interactive workflow and collaboration capabilities between agencies — a mandatory feature if the technology is funded by the Department of Homeland Security.
Also popular in forensic video analysis is Cognitech's Video Investigator software program. Cognitech began as a service company providing video processing on several high-profile cases like the Reginald Denny trial in 1993. Its Video Investigator software was introduced in 1999. Unique capabilities include Frame Fusion, which combines related moving and changing information from video frames, and JPEG Deblocker, which removes the blocking effect from low-quality compressed JPEG images. Integraph's Video Analyst system is another fixture in forensic video labs. Using NASA's Video Image Stabilization and Registration (VISAR) technology, Video Analyst allows the user to capture, analyze, enhance, and edit any type of video.
The three programs handle a variety of video formats since there's no prevailing standard in the industry. However, the Security Industry Association recently formed the Digital Video Standards Committee to develop a standard for digital security systems. “As for hardware, our favorite professional VHS deck is the Panasonic AG1980,” Humphrey says. “It plays well but unfortunately isn't manufactured anymore.”
While there are several software packages designed specifically for forensic video, audio software is derived from recording studio production tools. Mariasy, who has 25 years of recording experience, also runs a high-end recording studio in conjunction with the Team Audio forensics lab. “Between the lab and the studio lies similar equipment, but in different orientations,” he says. “Mostly we're using software restoration and archiving tools that were developed for use by Hollywood movie production or the recording industry.”
Sound Forge professional digital audio editing software by Sony is a popular choice, as is audio and music editing software by Sonic Solutions. CubeTec International offers a digital audio workstation called AudioCube that provides an integrated solution in the areas of restoration, mastering, archival, and DVD-A authoring.
For audio hardware, the list also reads much like a recording studio. Audio recorders by Marantz, digital and analog mixing consoles, and almost any brand of self-powered studio monitor will fit the bill. “The job isn't for the novice,” adds Calen Bruce of Team Audio. “In forensic audio, the incoming audio has a high noise-to-signal ratio unlike what you would encounter in a studio. Our work is much like archaeology.”
And whether you specialize in forensic audio or video, once you achieve a measure of success there's a high likelihood that you'll be called into court as an expert witness. “You'll need to have proper credentials,” Humphrey says. “It helps to take legal courses and be familiar with the legal process, get certified in the program you used to uncover the evidence, and also know how to properly handle evidence.”
It also helps to have a well-rounded background, including a basic understanding of computers and electronics, audio and video terminology, and the basics of both audio and video, regardless of your specialty. Most likely, if you're an audio specialist you'll probably be working in tandem with a video specialist. “Mostly it's experience and technique that yields results; not gear,” Sanderson says. “There may be many people who advertise forensic services, but you need to rely on experience. You need day-in, day-out forensic work to excel in this job.”
Linda Seid Frembes is a freelance writer and PR specialist for the pro AV industry. She can be reached at email@example.com.