![]() ![]() ![]() Modern video codecs integrate visual contents by periodically storing complete reference “i” frames, between a series of Fortunately, there is an effective work around. However, video authentication software can be priced beyond most budgets. Image and audio tests can be performed using free, or nearly free, There are hundreds of available authentication tests, and the Forensic Working Group has consolidated the most effective ones into a simple Multimedia Authentication Testing (MAT) worksheetįorm (3). The analyst should only rely upon, and denote, facts that they can personally attest to, and generally that will be limited to data extracted from the questioned file, and the manufacturer’s documentation regarding the equipment known to have created the questioned file. If the file is of a questionable or unknown origin, as is usually the case, then best practices should still be followed from that point forward. This means that the questioned files should be captured at their source, whenever possible, all work should occur in such a manner as to not alter the questioned files, and analysis should only be performed on exact file copies. This article provides a brief how-to look into the exciting world of multimedia authentication.Īs with all forensic work, it is important to follow industry best practices. Several groups, educational settings and web resources provide the required training and scientific understanding behind multimedia authenticationįorums (2) encourage forensic experts, newbies, scientists and scholars to share knowledge and refine their skills. In one case, I was able to prove thatĪ mobile phone video depicting an altercation, had been edited to present the perpetrator as the victim.Īudio Video Forensic Analyst's are the Trier-of-Fact, and their primary duty is to the facts. This is a real-world problem, and I have processed cases with edited phone conversations, modified accident photos, and altered dashcam footage. This a cat-and-mouse challenge and, while an absolute "Gotcha" conclusion is unlikely, an analyst can perform a suite of tests that collective lead to a substantiated summary opinion The remedy comes from ever evolving testing software and methods based on scientific research and peer review. ![]() Modern software automates the process of adding or removing a suspect or their weapon from an image, with the end results passing the most scrutinous visual examination. The attorney has a duty to investigate this claim, and the courts will exclude the evidence should this claim be true. A young man is on trial, and the primary exhibit is a video that the defendant claims to be a forgery. ![]()
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