Minneapolis police are about to join a growing number of cities where officers are testing the use of body cameras, a move that leaders hope will force police and citizens to be on their best behavior.

The change is raising tough new questions about how the cameras should be used at a time of growing public and political pressure for more accountability during police stops.

Mayor Betsy Hodges is encouraged by the potential of the new technology, but wants to make sure they are thoroughly tested before being implemented more widely.

"Just like anything else, you can't simply overlay the policies and practice of one city or state onto Minneapolis," said Hodges, a leading supporter of the body camera initiative. "We're our own unique city with certain dynamics and political makeup and community relationship that's different from most places."

A Minneapolis City Council committee gave tentative approval Monday to buy $170,000 worth of cameras and equipment for the test program. Final council approval is expected Friday.

The cameras can be clipped on eyeglasses or onto the front of a shirt and are intended to capture an officer's interaction with the public, providing potentially critical evidence in any dispute.

Cities and police departments are trying the new technology at a time of renewed and intense national focus on police accountability after the fatal shooting in August of an unarmed black teenager in Ferguson, Mo., a suburb of St. Louis.

Minneapolis has paid out millions of dollars in settlements for alleged police brutality and endured dozens of misconduct lawsuits filed against the department in recent years.

Police Chief Janeé Harteau said the department continues to refine its body-camera procedure. The city is authorized to spend up to $400,000 for the cameras this year and pledged another $1.1 million for the full body camera program next fall.

Locally, the body cameras are already being used in Duluth and Burnsville. Around the nation, police in cities like New Orleans and Oakland are using the technology, while Houston and Denver are considering it. A federal judge earlier this year ordered the New York Police Department to start using the cameras after ruling on its controversial stop-and-frisk program.

Under the testing program, two different camera systems will be assigned to 36 officers around the city for six to nine months.

One camera is attached to an officer's sunglasses, glasses or headband and follows his or her line of sight. The device is always on, constantly recording footage that is beamed to remote data storage where it can be accessed via a computer by anyone with clearance.

The other model is clipped on the front of the uniforms and can be turned on and off by the officer. The system is cheaper to manage, requiring less data storage fees, and gives an officer more discretion to turn it off, like during minor infractions or when talking to eyewitnesses who do not want to be recorded.

The second system could create a public relations problem, however, if officers fail to record encounters where use of force is required, said Teresa Nelson, American Civil Liberties Union of Minnesota's legal director.

Authorities also need to resolve privacy issues, she said.

For example, an officer on a domestic violence call would record footage of a suspect or victim, which could potentially become public record after the case has ended.

Law enforcement officials say the cameras will make both police and citizens more accountable and make interactions between the two sides more transparent.

A University of Cambridge study of the Rialto, Calif., police department found that use of the cameras led to an 88 percent drop in complaints filed against officers compared with the previous 12 months. The study noted a 60 percent decline in use-of-force incidents by officers over the same period.

The ubiquity of other recording devices — dashboard cameras, pole-mounted street cameras and smartphones — has ensured that many police-public interactions are already getting scrutiny. But body cameras portray a more nuanced and objective account than that of police or the citizens, supporters say.

"This camera also captures a perspective that may be different from both," said Duluth police deputy chief Mike Tusken, who runs the department's patrol division, which received the playing card-sized cameras in June. "It captures details that officers may have forgotten. It captures statements that are made by subjects that maybe they didn't hear or perceive at the time."

Tusken said the technology has not only proven to be a great training tool, but has helped drive down the number of complaints against police.

"Now we have another piece of the puzzle," he said.

Other law enforcement officials are more cautious, noting that once the public comes to expect real-time accounts of police interactions, it is almost impossible to scale back the program.

David Roberts, senior program manager at the International Association of Chiefs of Police, said the technology raises a lot of serious questions, including: How long do agencies hold onto the data? Who has access? Is this going to be publicly available information? Are police going to edit out certain portions of the video for the public?

"I don't think it's a panacea," Roberts said. "It has to be managed well and have policies in place that are strictly enforced."

Some experts say city leaders need to understand that while the equipment can be expensive, data storage can also be a significant long-term cost.

"You have to be realistic about this type of technology and the costs of storing this type of information," said William Farrar, the police chief in Rialto, Calif., one of the few places where the impact of the cameras has been studied. "It's not prudent for an officer to go out to a report of a stolen lawn mower and record it."

Farrar said, however, that law enforcement should not let questions prevent implementation. He recalled the resistance when police first got computers in their cars.

"We thought the end of the world was coming," Farrar said. "But now you can't work without one."

Libor Jany • 612-673-4064 Twitter:@StribJany