The San Francisco Board of Supervisors voted 8-3 Tuesday to approve a modified request from the San Francisco Police Department to allow the use of robots armed with potentially lethal explosives in certain circumstances. Approval of the controversial proposal followed two hours of emotionally charged debate, The Associated Press reports, with each side accusing the other of excessive fear-mongering. 

The San Francisco PD had proposed using robots “as a deadly force option” only “when risk of loss of life to members of the public or officers are imminent and outweigh any other force option available to SFPD.” The proposal was prompted by a new California law that requires police and sheriff departments to list their military-grade equipment and how it can be used, with city governments given final approval of those rules. 

The San Francisco supervisors did amend the proposal to stipulate that only a limited number of high-ranking police officers can authorize the use of robots for deadly force, and only after first using alternative tactics or concluding there was not other way to subdue a suspect. 

The San Francisco Police Department says it has 12 functioning land-based robots, not of them are currently armed, and it has no plans to equip any of its robots with firearms. But it wanted the ability to deploy robots with explosive charges “in extreme circumstances” in order to breach buildings or “contact, incapacitate, or disorient violent, armed, or dangerous” suspects when lives are at stake, a spokeswoman said.

Civil libertarians and the San Francisco Public Defender’s office had opposed the use of deadly robots, and some of the supervisors said they are concerned police will disproportionately use lethal robots on Black and other people of color. 

The military uses armed robots to kill enemies in war, but “that is not and should not be the purpose for police forces,” Paul Scharre, an expert on military use of autonomous weapons, told NPR News before the vote. “Once you’ve authorized this kind of use, it can be very hard to walk that back.”

The Oakland Police Department dropped a similar proposal amid a public backlash. The only known use of lethal robots by a U.S. police department was in Dallas in 2016, when police used a robot armed with explosives to kill a sniper who had ambushed police, killing five officers.