traffic stop

Austin Police move in-car video into the 21st century

Like many police departments, the Austin PD in Texas documents police activity with in-car video. But by 2009, its turn-of-the-century VHS recording system was showing its age, and the department was looking for a replacement. The tape-based system had to be activated manually by the officer and sometimes events were not captured. Duplicating tapes for the courtroom and investigators was labor-intensive and time consuming, repairs were becoming frequent and only one company was producing VHS tapes. It clearly was reaching end of life.

The obvious solution was to go digital, said Marcus Davis of the department’s Police Technology Unit. “Eventually, everybody was going to have to do this,” he said. “We saw a need, so it was at the top of our list of things to get done.”

The technology unit began looking at available technology in September 2009, and the city approved $15 million for a new system in 2010. By 2012 the Panasonic Arbitrator 360 in-car video system was installed in 550 marked patrol cars and on 75 motorcycles, uploading four terabytes of data each day to a state-of-the-art storage system over a new 802.11n wireless city network.

The full-motion camera has a zoom lens and can produce evidence-quality video under low-light conditions. One of the requirements for the system was the ability to automatically trigger the system so the officer wouldn’t have to remember to turn it on during an incident. The Panasonic system came with triggers that activate recording when the cars lights and sirens are turned on, and the Austin PD added another trigger to activate it when the car door was opened. This lets the officer concentrate on the incident at hand without worrying about getting the video.

But “we also needed the ability to do pre-event recording,” Davis said. If the video system is not activated until the lights and sirens go on or the officer gets out of the car, it could not include the activity that spurred the police response. So the Panasonic system works continuously, buffering the images but not writing them to memory. Once the system is triggered it saves video from several seconds before the trigger is activated.

One of the biggest challenges in implementing the system was handling the large volumes of data being produced. The city had an 802.11b/g Wi-Fi network, but its bandwidth was not up to handling the data being uploaded from hundreds of cars several times each day. The network was upgraded over the course of a year to 802.11n, which has a data rate of from 54 to 600 megabits/sec. Video is written to an on-board SD card, which automatically sends it to an upload server at one of four department substations when the car is in a hot spot. From the upload server data is transmitted to a central storage-area network. To ensure that video is uploaded as soon as possible without the patrol car having to idle in order to power it, the system includes an auxiliary power supply that can support four hours of upload when the car is not running. With this system, 95 percent of video is uploaded within 24 hours, and the city’s carbon footprint is reduced by decreasing idle time for cars.

Storage costs were reduced by 67 percent by improving the way video is tagged for use. Each recording is tagged with an average of three codes, which determine how long the data must be retained. In the past video would have been stored three times. With the new system it is stored once with three pointers. The tagging is expected to save $3 million in storage costs over five years.

About the Author

William Jackson is freelance writer and the author of the CyberEye blog.

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