Faculty Publications

Document Type


Publication Date

March 2019

Publication Title

Journal of Forensic Sciences






Forensic science, speed calculation, forensic video analysis, frame timing, reverse projection photogrammetry


Criminology and Criminal Justice | Forensic Science and Technology


The prevalence of security and in‐car video has increased the number of motor vehicle accidents captured on digital video. However, inconsistencies in how to accurately determine time and distance for vehicle speed has led to examinations with varying results. A potential solution for calculating time intervals is to use frame timing contained within many digital video file's metadata, recorded with 0.000001 sec precision. This paper examines a fatal motor vehicle accident where frame timing information was used with distance measurements from reverse projection photogrammetry to calculate vehicle speed. A margin of error was then calculated based on the accuracy in performing reverse projection photogrammetry distance measurements. The resulting speed calculation was then compared to event data recorder data and found to be within an average of ±1.43538 MPH. Using specific time intervals may lead investigators to more accurate speed calculations, specifically those involving variable frame rate video.


This is the pre-peer reviewed version of the following article: Epstein, B. and Westlake, B. G. (2019), Determination of Vehicle Speed from Recorded Video Using Reverse Projection Photogrammetry and File Metadata. J Forensic Sci. doi:10.1111/1556-4029.14053, which has been published in final form at https://doi.org/10.1111/1556-4029.14053. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
(Presented at the 71st Annual Scientific Meeting of the American Academy of Forensic Sciences, February 18‐23, 2019, in Baltimore, MD.)