A Minneapolis police officer is under investigation by federal authorities

Federal authorities are investigating a Minneapolis police officer who has been the target of two brutality lawsuits that have cost the city $410,000.

The investigation focuses on Michael Griffin, a patrol officer in north Minneapolis, who joined the police force in 2007.

Griffin has been the subject of 22 police internal affairs investigations, a total that may include both public complaints and internal department issues. Most of the claims against him were not upheld.

The U.S. attorney's office declined to comment. However, a number of sources told the Star Tribune that the FBI has been making inquiries that include questions about two excessive force lawsuits in which Griffin was accused of punching or kicking people while he was off-duty at downtown bars. The sources spoke on condition that they would not be identified.

A number of Minneapolis police officers reportedly have been questioned by the FBI and told to be prepared to give testimony to a federal grand jury.

"I am troubled that any grand jury process would be reported on by the media," said Ryan Kaess, a St. Paul attorney, who said "at this point," he is Griffin's lawyer. Kaess described Griffin as "a fine police officer," but declined further comment.

John Elder, a spokesman for the Minneapolis Police Department, said that due to the federal investigation, his office was not allowed to discuss it.

Five other cases — two from 2013, one from 2014, and two from 2015 — remain open.

The possible prosecution of Minneapolis police officers occurs at a time in which police have been under the microscope across the nation over allegations of misconduct, including alleged brutality and the shooting deaths of several black people.

Griffin is black. Complaints against him have come from both white people and people of color.

Prosecutions in Minnesota for police misconduct are highly unusual.

The Justice Department prosecuted Minneapolis police officer Jason Andersen, a member of the now-defunct Metro Gang Strike Force, over the kicking of a black youth in Crystal. He was found not guilty in 2010.

The Justice Department reviewed the allegations but took no action beyond Andersen's prosecution. The Hennepin County attorney's office declined to prosecute. Hennepin County attorney Mike Freeman said at the time that he was hampered because Strike Force officers declined to talk to investigators.

Griffin won a departmental medal of valor for his response to the 2012 multiple shootings at Accent Signage.

"When Michael Griffin first came on to the department there were high expectations of him," says Ron Edwards, a longtime civil rights activist, who is a member of a police oversight group appointed by Minneapolis Police Chief Janeé Harteau.

"But at some point down the road he lost perspective," Edwards said. "The department has really tried to work with him and tried to work through his problems, but it's quite clear that some of the incidents have caught the attention of federal investigators and now his fate is in their hands. I still think that he would make a good police officer with a productive career, but he needs help with his problems."

In January 2014, a jury awarded $125,000 to Jeremy Axel, an IT salesman from St. Louis Park, in his suit claiming that Griffin challenged him to a fight in a Minneapolis bar in 2011, then knocked him out, leaving him with a concussion. In March 2014, U.S. District Judge David Doty ordered the city to pay Axel's attorney $145,653.