Independent investigators with both the city and Axon, the device maker's parent company, will search for answers.

Despite concessions by the department following public outreach, the groups calling for changes are now joined by law firms.

New York City police have been working with researchers to collect public feedback on their policy to govern the use of the technology.

Though the city is currently wrapping up its own pilot of the technology, a new bill would set up a two-year program with select NYPD officers.