IOWA CITY, Iowa — State legislators are pushing to make it much harder to release police officer body camera videos, undermining their promise as a tool people can use to hold law enforcement accountable.

Lawmakers in at least 15 states have introduced bills to exempt video recordings of police encounters with citizens from state public records laws, or to limit what can be made public.

Their stated motive: preserving the privacy of people being videotaped, and saving considerable time and money that would need to be spent on public information requests as the technology quickly becomes more widely used.

Advocates for open government and civil rights are alarmed.

Police departments nationwide are already spending millions to outfit officers with cameras and archive the results. In this latest clash between the people’s right to know and government authority, the responsibility to record controversial encounters, retain copies and decide what to make public mostly rests with the same police.

Absent public records protections, these police decisions can be unilateral and final in many cases.

“It undercuts the whole purpose of the cameras,” said Michelle Richardson, public policy director of the American Civil Liberties Union of Florida.

“People behave better on film, whether it’s the police or the suspect, because they realize others are going to see them. When you take away that possible consequence, you really undercut the oversight value of these,” she said.

Supporters say the privacy rights of crime victims and witnesses need protecting, and that police need to limit the broad and costly public records requests they’re getting. Routinely releasing these videos will deter people from calling for help and cooperating with police, they say.

“Public safety trumps transparency,” said Kansas state Sen. Greg Smith, a Republican. “It’s not trying to hide something. It’s making sure we’re not releasing information that’s going to get other people hurt.”

Bills that would restrict access to body camera footage :

— Minnesota: Senate File 498 would treat the videos as private records, available only to those who are the subjects of the recordings.

— Iowa: House File 452 says body camera recordings “shall be kept confidential.” People who are featured in them and their representatives would be able to view and copy the recordings.

— North Dakota: House Bill 1264 says any image “taken by a law enforcement officer with a body camera or similar device and which is taken in a private place” would be exempt from disclosure. The North Dakota House voted 87-3 to pass it Jan. 30.