Article by
Kelly WattDirector of Sales & Business Development

In State of New Hampshire v Witty, the prosecution’s traffic accident expert examined video evidence and used the on-screen date and timestamp to determine vehicle speeds. The collision expert failed to authenticate the timestamp and admitted that he had received no training in how to examine video evidence, nor how to access metadata in video files that might have exposed the actual video timing.

Inset Image of Dump Truck with Program Time Stamp Witty’s dump truck, depicted in the inset image, collided with two vehicles in an intersection, causing the death of one of the drivers. The crash analyst relied on the on-screen timestamp for his speed estimation.

Defense expert, Grant Fredericks, used iNPUT-ACE to access hidden metadata in the video images. The iNPUT-ACE frame analysis report showed that the video was recorded at a variable image refresh rate, rather than the even image playback rate purported by the on-screen timestamp. In a pre-trial hearing, Fredericks demonstrated to the court that a proper analysis of the video metadata showed that there was no foundation for the state’s vehicle speed evidence. Parking lot view of crime scene shown in the iNPUT-ACE user interface.

Jonathan Hak, a former prosecutor and leading expert in the admissibility of video evidence, examined the court’s decision, and in his blog he outlined that anyone conducting speed estimation from video images should seek training in that area. Hak describes that the court agreed with Fredericks, ruling that the date and time stamp could not be shown to the jury. The court also said that the video could be played only as a series of still images, rather than motion video, and that no speed evidence was permitted to be presented to the jury.Image Refresh Rate Report

“INPUT-ACE allowed me to easily determine that the on-screen timestamp was inaccurate and was not fit for the purpose of speed estimation”, says Fredericks. At the pre-trial hearing, he explained to the court that on-screen date and timestamps are often misinterpreted, as they usually represent only an approximation of timing. “The truth or meaning of video is not confined to what we can see on the screen,” maintains Fredericks. “Often the most valuable evidence is contained within the metadata of video files.”

Fredericks, who has been an instructor at the FBI National Academy in Quantico, VA for the last sixteen years, teaches traffic analysts and police investigators how to accurately interpret video evidence. His course Video Examinations for the Police Investigator is being offered throughout the US and Canada in 2019. The course focuses on Use of Force, Speed Estimation, and Major Crime case video examinations. The 2019 course schedule will be released soon at