Forensic Video Analysis: Training To Be a Forensic Expert and Getting Needed Equipment

• NCJ Number: 189231
• Journal: Law Enforcement Technology Volume: 28 Issue: 6 Dated: June 2001 Pages: 34-36,38,39
• Author(s): Grant Fredericks
• Date Published: June 2001
• Length: 5 pages
• Publication Format: Article
• Publication Type: Instructional Material
• Language: English
• Country: United States of America
• Note: Part II of a two-part series.

Annotation

This article identifies and discusses the features of an effective forensic video analysis system.

Abstract

Police agencies overwhelmed by the increasing amount of videotaped evidence seized from private business are facing such questions as what forensic video analysis equipment will do the best job for the dollar and where investigators can be sent for training. In 1953, the National Television Standards Committee (NTSC) established a single standard for all video broadcasting. A forensic video analysis tool must be capable of recording the full NTSC broadcast signal (non-square pixel matrix of 720x486 when digitized for examination), which is what most closed-circuit TV (CCTV) security videotapes capture. Equally critical is the forensic video equipment's ability to work with digital images. Further, it is essential that a digital analysis tool be capable of viewing the odd or even field of a video frame and that it be capable of viewing both at the same time. Without this capability, the analyst could be missing up to half of the actual images recorded to tape. In addition, since a large percentage of CCTV analog and digital security systems encode multiple cameras to a single video channel, the equipment of the forensic video analyst must have the ability to digitally decode a multiplexed image; this will allow the examiner to select a specific camera and play back only that camera angle. Other important features in a forensic video analysis system include easy-to-learn and easy-to-use editing tools, image tracking capabilities, image stabilization, frame averaging, and the ability to track tool settings and analysis histories in order that each step can be repeated at a later date in court. Also discussed in this article are training in the use of acquired equipment, support from peers who use the same type of equipment, the services of the Law Enforcement and Emergency Services Video Association, and the importance of a police agency's having a video unit to examine video-based evidence.