In late June 2009, the Supreme Court ruled in Melendez-Diaz v. Massachusetts that certified reports from experts or forensic analysts were no longer admissible as evidence unless the author was made available for cross-examination by the opposing side. A lab worker’s conclusion regarding the nature of seized substances (identified by the analyst as cocaine) was at issue, the complainants argued, since they were never afforded the chance to confront the lab worker in court about the analysis. The Supreme Court essentially ruled that this violated the right of defendants to face their accusers.

WAYNE COLE

VIDEO ANALYSTS
Most forensic video analysts I’ve met over the last 15 years are either police officers who have transitioned from field work to the “lab” or CSIs primarily trained in gathering and processing of organics, fibers, ballistics, fingerprints and other forms of physical evidence. Video training is usually limited to how to use the various tools for video isolation and enhancement. In other words, these technicians learn about the tools, not about video.

For years, video “experts” have been able to “certify” that the video contains certain information and courts usually accept such “evidence” as factual and indisputable. The opposition can challenge the conclusions but rarely gets to challenge how they were reached. Video evidence can make it to court with accompanying conclusion that cannot be supported by objective scientific processing methods. It isn’t that video techs lie; they just do not have the technical training or experience, in many instances, to see past what the ordering agency wants them to see.

An extreme example of “facts that aren’t” was demonstrated in a case that recently made the “Wicked Attraction” series on the Investigation Discovery channel. In California v. Golay and Rutterschmidt, there was a contention that a vehicle owned by the defendants was detected on security video leaving the scene of a homeless man’s hit-andrun death for which the defendants tried to collect a life insurance payout. I was consulted prior to the trial regarding this video by Digital Evidence, a firm hired by the defense to review the video. Without being told the facts of the case, I was asked to see if I could identify a vehicle or driver from a number of clips taken from typical commercial video security systems. There was no accompanying data, like site measurements, camera distances or lens data. The quality of the video was so bad that all the vehicles appeared as moving, amorphous blobs even after enhancement using various forensic video tools. There was insufficient information to ID a vehicle make or model either by clear visual markings or by photogrammetry and comparison of measurements to vehicles in a database like Expert AutoStats. Yet, according to the television program, police made an identification based on their interpretation of window shapes. Fortunately for California’s homeless population, there was other more compelling evidence (including the defendants’ own taped conversations) that made the security video largely irrelevant.

WHO’S AN EXPERT?
The Golay case was one in which conclusions drawn from incident scene video were not a deciding factor. In other cases, security video may be the key evidence. The Supreme Court’s recent decision increases the likelihood that any conclusion drawn will have to be supported by testimony of the person( s) responsible for collecting and processing the video. Even before getting into the witness box, video evidence handlers may have their qualifications challenged by attorneys smart enough to consult their own video experts.

Because of low native video resolution, attempts to magnify the vehicle (yellow box) quickly break down to indistinguishable, blocky blobs.

Many times, technical arguments against video are made to confuse a judge and jury, resulting in the impeachment of what may otherwise be valid evidence. I have previously alluded to how the understanding of 24p and 2:3 pull-down technical issues was used to impeach analysis of video that had been converted from film for use in court. Most police or public safety forensic lab video techs would be incapable of explaining how such technology works in a way that juries could grasp.

Another area ripe for attack would be to have a video tech try to explain how MPEG-2 or MPEG-4 compression does not constitute “alteration” of captured video making it inadmissible. The opposition can testify that MPEG temporal compression throws most of the actual video frames away and replaces them with predicted (i.e., guesswork) pictures. Remember, most judges are not tech-savvy either, and a ‘silver-tongued’ “expert” could produce a winning argument for disqualification that has no real relevance to the video’s evidentiary value.

INCREASED RESOURCES
The Melendez-Diaz decision means that more resources for technical training and giving live testimony may be needed to support forensic video technicians. Reproducibility of results will likely be more tightly scrutinized. This will require more detailed documentation of any video processing to be captured as the video is processed. And those doing the processing will need more in-depth knowledge of what their tools are actually doing: “Did you use a convolution matrix in your processing, and can you explain to the jury how that impacted the video?”

Could the Supreme Court’s ruling also impact forensic video tool developers? If written specifications indicate that a tool only enhances rather than alters video, would the developer also have to testify, for example? Attorneys facing strong video evidence may push this ruling to extremes to get the video excluded. That means every forensic video technician in the field, the lab or private practice needs to immerse themselves in the technology of video and their tools so they can testify about them in ways that juries can understand.