A new sensor designed for law enforcement can alert an officer's body cameras to start recording automatically when a weapon is drawn. The Axon Signal Sidearm from TASER International is a wireless sensor that attaches to an existing police firearm holster and integrates with the company's Axon line of dash cameras, body cams and other wearable cameras.

When a gun is drawn from a holster with the sensor, it triggers all Axon cameras within 30 feet (9.1 m) to start recording, simultaneously providing a record of events from different perspectives without the officer having to remember to press any buttons.

The wireless sensor is powered by a coin cell battery that the company says will last about 1.5 years, alerting the Axon network when it needs replacing.

A 2016 study found that complaints against police officers drop significantly when a body camera records an incident. Similar wireless systems exist that record timestamp and geolocation data for firearm use, but they don't trigger any other sort of recording.

The company says the Signal Sidearm will be available for purchase in Q3 2017.

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