In-Car Video: Compelling Evidence - Technology and Communications -

In-Car Video: Compelling Evidence

In-car video increases convictions & eliminates false claims



Teresa McCallion | From the April 2009 Issue Wednesday, April 1, 2009

We've all seen them. Heck, some of you may have even starred in them. "They" are the videos recorded by in-car systems during real-life arrests, high-speed chases and shoot outs. These videos provide late-night entertainment for millions of television viewers. More importantly, the technology provides compelling evidence that's often used to increase the number of convictions, eliminate false claims against law officers, enhance officer safety and improve training.

"On-board video is the best thing going," says Little Elm (Texas) Police Department Assistant Chief Ric Sadler. "It comes in handy on a daily basis." According to Sadler, even stop sign violators in Little Elm who come to court to fight a ticket are less confident of their innocence when confronted with video evidence of their misdeed.

Lawmakers in Texas are so convinced of the value of these recording devices that they've mandated their use in that state, Sadler says.

In-car systems have been deployed in law enforcement vehicles since the early 1980s. Those early units were adaptations of civilian-based analog video cassettes that produced high-quality images, but were not built to withstand the gritty, and sometimes grimy, world of law enforcement. Reusing videotapes produced unfortunate degradation and created cumbersome storage issues. If the evidence was requested, locating a specific event often involved a tedious search through hours of mind-numbing video.

Since then, digital systems specifically designed for use by law enforcement have replaced analog tapes, improving the quality of the images, storage capacity and functionality. Commercial (as opposed to consumer) grade devices are less likely to fail in the demanding environment of a police vehicle. Security and authorization features have been added to help prevent tampering or destruction of evidence by criminals inside the vehicles. Further, security enhancements, such as wireless transfers, help establish the authenticity of the data and maintain the chain of evidence. Because most of the new systems use compressed file formats, media storage requirements can be scaled back. A further advantage of digital data is that the system can automatically generate metadata tags that make it easier to

locate a specific event.

One of the most beneficial technological advances of a digital system is the pre-event recording feature. It captures not only the officer's actions, but also the events leading up to them. Some units, such as Safety Vision's PatrolRecorders, include the ability to record associated data, such as the officer's identification, department and radar speeds. Imbedded global positioning system (GPS) chips even record location data.

Event Recording
In most of the devices, the camera is always on, but it requires some sort of signal to trigger it to begin recording. The recording might start automatically when an officer flips on the light bar or siren, or an officer may activate it manually when he or she turns on the wireless microphone. Crash sensors that monitor rapid acceleration and deceleration also trigger most systems.

Whenever the device is activated, it automatically stores the video and audio for a set period of time usually 60 seconds preceding the event. This pre-event recording feature is handy for capturing the "probable cause" that led to the traffic stop, for example, allowing judges and juries the opportunity to put the officer's actions into context.

The recording ends either when the lights or siren has been turned off or when the officer manually stops the recording. Some systems include an indicator to alert the officer when the unit is still recording.

To get a clean audio recording, offi cers wear a microphone during their shift. The audio data are recorded on separate tracks from the video.

"The nice part of digital systems is that they will accept more than one microphone per digital frequency," Carbondale (Ill.) Police Department Interim Chief Jeff Grubbs says.

Most systems offer the option to install a rear-facing camera in addition to the front-facing unit. Prisoner and officer conduct can be recorded and used as evidence should a question arise regarding the events that transpired during transport. Microphones located inside the police car can be installed to record audio evidence.

Some agencies have found that visible cameras actually encourage prisoners to be on their best behavior, although other agencies prefer a more covert operation.

Because this camera is often required to work in a low-light environment, rear-facing cameras use infrared technology to improve image quality.

Previously, most recording devices were located in the trunk, concealed from prying eyes. However, it was less convenient for the officer to access the unit to transfer data. Today's equipment, while typically more compact, often resides within the vehicle's cabin.

Of course, locating available space inside a cruiser for all of the components of a recording system can be a challenge. The Carbondale PD found that since it already used Hub-Data911 units for its in-car computers, adding the video system from the same company allowed it to consolidate components. "We actually were able to remove equipment instead of add it. All control functions are manipulated though the [existing] touch screen system," Grubbs said. "That was the first time we have ever been able to say we removed equipment."

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Teresa McCallionTeresa McCallion EMT-B, is a freelance public safety writer in Bonney Lake, Wash. Contact her at


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