Q: What do you mean by video and audio forensics?

A: According to the American Heritage Dictionary, the classic primary definition of the word forensics is “the art or study of formal debate; argumentation”. In the context of video and audio it is the second and more contemporary definition we’re concerned with: “the use of science and technology to investigate and establish facts in criminal or civil courts of law”. The goal of a forensic examination of a video or audio recording (or both) is to obtain evidence that is not readily apparent by watching or listening to the recording with standard equipment; that is, evidence that might otherwise be missed. There are actually two possible parts of an examination: 1) to authenticate the recording, and 2) to enhance the visual or auditory details of the recording, depending on if it’s video or audio.

Q: What do you mean by “authenticate”?

A: To authenticate a recording or photograph means to state that it is genuine (has not been tampered with to add or remove evidence) and that it is a fair and reasonably accurate representation of what it is supposed to be a recording of. For example, a digital image of a person modified to alter their appearance cannot be legitimately authenticated. There are methods of determining if most types of recordings, analog and digital, have been tampered with, but they won’t be detailed here because the goal of this FAQ is not to teach people how to make better forgeries.

Q: What kinds of enhancement can you do?

A: With video, it’s possible to track motion to stabilize “shaky” hand-held video, track and highlight or obscure a person or object of interest (a suspect or weapon might be highlighted, and a confidential informant, undercover police officer, or minor might have their face obscured). The histogram can be adjusted for optimum lighting and contrast, an area, person, or object of interest can be enlarged, and the video underscan area can be resized so that details outside the borders of an ordinary television set can be seen. It’s often possible to obtain a much higher resolution still frame from several sequential video frames and objects within a video frame can be measured if there are sufficient reference measurements available. With an audio recording, the goal is to reduce noise that interferes with the conversation while increasing the intelligibility of the speakers’ voices. Telephone and electrical hum and noises, motor vehicle and road noise, crowd background noise, and noises cause by consumer grade tape and digital recorders themselves can all be reduced, often substantially to improve the ability of a listener to discern a conversation. In many cases, even background music or television audio can be subtracted by digitally subtracting a reference recording to enhance the conversation.

Q: Can you zoom in and enhance to read a license plate or obtain facial identification?

A: In some cases yes, and in other cases it’s simply impossible. This is one of the most common requests we get from members of the public, probably because of the popularity of television shows like “CSI” and its Miami and New York spin-offs. Like virtually every other aspect of these shows, scenes simulating “video enhancement” are exaggerated to the point of absurdity. Television crime lab heroes can magically “zoom in” on video of a microscopic detail on an object hundreds of yards away and enhance it with crystal clarity in seconds, and even rotate a two dimensional image of a three dimensional object to expose details that weren’t even captured by the camera! In the real world, forensic examiners must obey the laws of physics. The harsh reality is that only a lens system can zoom in on anything. Forensic video hardware and software can only rescale (enlarge) a section of an existing video recording. Better yet, we can do so using algorithms that enlarge without simply magnifying pixels and distorting, or “pixelating” the image the way that consumer software would. This may very well make an object or person easier to see or identify, but there is NO equipment or software that can create details that weren’t recorded in the first place.

Q: Can the government use some sort of special software that you don’t have to get more out of recordings?

A: Actually, Covert Sciences uses the very same software and methods as many local, state, and federal law enforcement and intelligence agencies, including the FBI and CIA. While video and audio forensic processing techniques and principles of operation are certainly complex, there’s nothing “secret” or “classified” about how the technology works. In fact, the software and techniques used for video and audio forensic processing are well documented in scientific publications and MUST be accepted within the scientific community in order to be accepted as evidence in a court of law.

Q: Shouldn’t I use a local examiner to process my video or audio?

A: While you’re certainly free to engage any expert you choose, geography should be the least significant consideration. Video and audio forensic analysis is a highly specialized field, with only two dozen or so examiners practicing in the private sector nationwide. As long as the chain of custody is maintained when shipping or transporting evidence, sending recordings to a distant lab for processing is a routine, accepted practice.

Q: I’m worried about sending the original; can’t I just send you a copy?

A: If the recording is analog, for example a VHS, 8mm, Hi8, or similar videotape or cassette or micro cassette audiotape, it is absolutely critical that you provide the original. The practical reason is that even the first copy of an analog recording suffers from what’s known as “generation loss”. The first copy of a VHS tape loses approximately 40% of the detail contained in the original. That’s 40% of crucial evidence that could make or break your case. The legal reason relates to the “best evidence rule”, which requires any evidence tested or presented to be the best available, preferably the original. If you have an existing recording on a CD or DVD and that’s all you have, exact duplicates are acceptable. However, transferring or “dubbing” an analog video or audio recording to CD or DVD is NOT acceptable, because of the relative certainty that your equipment, or even that of most professional studios would not accurately transfer all of the signal, or that the digital recording would use an unacceptable form of compression. Covert Sciences uses an accepted non-destructive digital capture procedure, and your original will be returned to you in the condition you sent it, with one exception: if you send a tape, the erasure prevention tab will be removed to prevent any possibility of accidental erasure or evidence compromise.

Q: How do I send you the recording?

A: Carefully package your tape, CD, or DVD in a “bubble wrap” mailer (available from most office supply stores) and pack the envelope wrapped in additional bubble wrap securely within a sturdy box, enclose completed and signed Video Policy, Chain of Custody, and Credit Card Authorization forms (available from the form download section of this site) and ship the package to:

Attn: Jeff Spivack
Covert Sciences
334 East Bay Street, #235
Charleston, SC 29401

Be sure to indicate if the recording was already damaged prior to shipment; in many cases we can reconstruct damaged tapes.

Q: How much do you charge?

A: The fee for conducting forensic video and/or audio analysis and processing is $150.00 per hour. There is a two-hour minimum for all projects, and the fee includes your first data or audio CD, DVD, and/or photographic print. Additional CDs, DVDs, and prints are billed at $10.00 each. The fee also includes return shipping via US Postal Service Priority Mail. Return shipping via overnight courier is available for an additional charge.

Q: How many hours and how long will it take to process my material?

A: Each project is unique, and processing time depends on many factors. Please call toll-free 877-828-1191 to discuss your recording in detail, including the goals for the project. You’ll receive an estimate based on the information you provide, with no obligation for the initial telephone consultation. Most projects are completed within 2 to 3 business days from the date of receipt.