Citation

Epstein B, Westlake BG. J. Forensic Sci. 2019; ePub(ePub): ePub.

Affiliation

Department of Justice Studies, San Jose State University, San Jose, CA, 95192.

Copyright

(Copyright © 2019, American Society for Testing and Materials, Publisher John Wiley and Sons)

DOI

10.1111/1556-4029.14053

PMID

30919949

Abstract

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.

© 2019 American Academy of Forensic Sciences.

Language: en

Keywords

accident reconstruction; forensic science; forensic video analysis; frame timing; reverse projection photogrammetry; speed calculation; video metadata