Klaus-Dietmar Gabbert / Getty Images

The Golden State is one step closer to banning police departments from using facial recognition in body cameras. The California State Senate voted Wednesday to approve a bill that would prevent police from using the two technologies together for three years.

The bill arises from concerns that facial recognition isn't reliable enough to use without flagging high rates of innocent people for questioning or arrest. Advocates also argue that adding facial recognition to body cameras creates a surveillance tool out of a technology that was supposed to create more accountability and trust in police departments.

It's not currently common for police departments to use facial recognition in their body cameras, but privacy advocates worry it could happen soon.

"Face-scanning police body cameras have no place on our streets, where they can be used for dragnet surveillance of people going about their private lives, including their locations and personal associations," Matt Cagle, technology and civil liberties attorney for the ACLU of Northern California, said in a statement.

The bill is poised to join a wave of other laws that restrict the use of facial recognition and other surveillance technology. San Francisco was the first city to pass a ban on city departments using facial recognition, and multiple other cities have passed similar laws since then. Cities are also taking an increased interest in laws that require police departments to get public buy-in for new and existing surveillance technologies.

Tech companies have also voiced concerns, with body camera maker Axon saying in June it wouldn't use facial recognition software in its products. Microsoft called for federal requirements that companies test facial recognition for accuracy and don't come with built in biases. Studies have shown that some facial recognition software is less accurate when judging images of women and people with darker skin.

The California State Assembly must vote on the bill and the governor must sign it before it can become law.