Videotaping a Crime Scene
A high-quality digital video camera used by law enforcement includes the three-CCD Canon GL2 Mini-DV.
Probably the most common law enforcement video application is recording a crime scene. The goal of videotaping a crime scene is identical to still photography: to record a reasonable and accurate representation of the crime scene. This means video should be taken before any evidence collection takes place, and usually before still photos are taken. A cover sheet helps to identify the location, date and time, type of scene, and photographer. It's also a good idea to turn on and properly adjust the camera's date and time stamp.
Before he or she begins shooting, make sure the videographer is familiar with the equipment, including advanced features of the camera. It is often beneficial to manually set the gain or white balance. Gain determines image brightness. White balance ensures that color is neutral and accurate under different light sources such as daylight, fluorescent light, and incandescent light.
Start shooting outside of the scene and work in, from a wide field of view to a narrow field of view. Many different techniques can be used to record a scene but always work slowly and methodically. It is often helpful to have a spotter walk directly behind the videographer to prevent him or her from disturbing any part of the crime scene; it's all too easy to be wrapped up in the videotaping and miss evidence right in front of your feet.
Another High-quality digital video camera used by law enforcement includes the extremely compact Sony DCR-IP5 Micro MV.
While shooting, imagine that you are a juror watching the tape and videotape the scene in such a way that it will allow a juror to understand the scene and the spatial relationships of the evidence within. Effective techniques include entering a room and slowly panning up and down, covering all of the surface areas in the room from floor to ceiling. Once the overall shots of a room are complete, zoom in to specific items of evidence. Linger on the evidence for an appropriate amount of time, slowly zoom out, then pan to the next piece of evidence.
Video and the Court
Legally, the issues surrounding video evidence in court are really no different than those for still photography, whether silver based or digital. The fundamental concern is whether the video shows an accurate reproduction of the scene.
Many law enforcement agencies worry about digital technology as it relates to forensic imaging. The primary reason for their anxiety is the ease with which digital images can be altered and manipulated.
But it is much harder to fabricate a believable altered video than most people think. Video consists of approximately 30 still images per second. In order to alter video, each frame must be altered individually-this could easily mean hundreds of frames for just a few seconds of footage. Software exists that automates special effects, but these programs are very costly and are primarily used in digital special effects for television and movies.
Still, the potential exists for both analog and digital video to be altered.
So how do law enforcement agencies ensure that video imaging is still admissible in court? The answer is simple. Demonstrative evidence such as video and still photography does not stand on its own in a court of law. The veracity of the images is not based on the technology, but rather on the person testifying to the authenticity of the video footage.
It's also important that the original videotape is kept in evidence. The tape should be copied, or digitized, and the original kept intact.
Always be straightforward with the defense if the tape has been edited. There is no problem with editing evidentiary tapes under certain circumstances such as surveillance tape that runs for three hours until the suspect can be seen. Just be sure that both the defense and prosecution are aware of the edit before the court date.
If the original tape is not used in court, John Pickering of the Boulder County (Colo.) District Attorney's Office recommends the officer, detective, or evidence technician view the copied tape before taking the stand to confirm that the copy is accurate.
Many agencies also use covert audio and video to record interviews and interrogations. While it is not absolutely necessary, it's a good idea to have signs placed at all entrances to the police department stating that persons entering the building are subject to audio and video monitoring. If a videotaped confession is used in court, the signs help alleviate protests from the defense attorney that his or her client didn't know they were being recorded.
Video is a powerful tool; if agencies follow reasonable guidelines and handle the original evidence carefully, defense attorneys will have a difficult time questioning the authenticity of video in court.
For more information
Law Enforcement/Emergency Services Video Association
David Spraggs is an investigator and firearms instructor with the Boulder (Colo.) Police Department. He teaches forensic photography and crime scene investigation.