Hennepin County Attorney Mike Freeman will attempt something that no prosecutor in Minnesota has accomplished in recent memory: Hold an officer criminally culpable for an on-duty killing.

In Minnesota, at least 164 people died in force-related encounters with police between 2000 and the end of 2017, and the only other officer charged in that period, former St. Anthony police officer Jeronimo Yanez, was acquitted of second-degree manslaughter in the 2016 shooting of Philando Castile in Falcon Heights.

“We gathered every piece of information, no matter how minute. We looked at the tragic night from every perspective,” Freeman said. “Then we saw the evidence clearly conformed to the statutory definitions of third-degree murder and second-degree manslaughter. Then, and only then, did we charge officer Noor with these crimes.”

The unusual charge of third-degree murder and the revelation Tuesday that Mohamed Noor’s former partner, Officer Matthew Harrity, told investigators he feared for his life that night could both complicate prosecutors’ effort to gain a conviction against Noor, according to several defense attorneys interviewed Tuesday.

Just before Noor shot and killed Justine Ruszczyk Damond in south Minneapolis last summer, Harrity said he heard a voice, a thump behind the squad window and caught a glimpse of a person’s head and shoulders, the charges said.

Harrity “perceived his life was in danger, reached for his gun, unholstered it and held it to his rib cage while pointing it downward,” the charges said.

Under state law, on-duty officers can use deadly force to protect themselves or their partners from apparent death or great bodily harm. And a 1989 Supreme Court decision requires that officers’ use-of-force actions be viewed in the moment, not with 20/20 hindsight.

“Officers are allowed to use deadly force that the average citizen can’t,” said attorney Ryan Pacyga. “Both officers were startled.”

Harrity’s statements that he took his gun out due to a perceived threat to his life are “good evidence for Noor,” said attorney Joe Friedberg.

But the fact that Harrity didn’t fire his gun will be used by prosecutors to make their argument, said attorney Marsh Halberg.

“There are a lot of facts on both sides to work with,” he said.

Conviction of third-degree murder requires prosecutors to prove that Noor had a “depraved mind” at the time of the shooting. But there’s no legal definition for a depraved mind, said Friedberg. He sees the murder charge as a potential negotiating tactic for Freeman, one that he could drop if Noor agrees to plead guilty to manslaughter.

Pacyga said prosecutors would likely avoid the “depraved mind” terminology and ask that jury instructions substitute the words “reckless conduct,” which is typically done in Minnesota.

“What it comes down to is what Noor was really feeling and experiencing at the time of the shooting,” he said. “He hasn’t given a statement, and only his lawyer knows his story. This may or may not come out in trial, if it goes to trial.”

At his news conference Tuesday, Freeman acknowledged the rarity of the charge by citing the findings of a recent study by Philip Stinson at Bowling Green State University and the U.S. Department of Justice.

The study found that of the estimated 12,000 police-involved shootings between 2005 and 2017, 80 officers were charged with murder and manslaughter. Of those charged, 35 percent were convicted.

But Freeman also mentioned his record in filing criminal charges against 17 law enforcement officers since 2010. Among them, 11 were Minneapolis police officers. Officers pleaded or were found guilty of assault, burglary, theft and solicitation of minors. Others have been found not guilty.

In October, former Minneapolis officer Christopher Reiter was convicted of first-degree assault for kicking a man’s face. Last month, Officer Efrem Hamilton was acquitted of assault and other charges for shooting at a car full of people during a downtown melee.

“I don’t have any bias against Minneapolis police. We work with them; we need cops,” Freeman said. “But we need cops to be law abiding. And in this case … clearly officer Noor violated the rules and deserves to be charged.”

Attorney Earl Gray was part of the legal team that helped acquit Yanez, who was charged with second-degree manslaughter and reckless discharge of a weapon in the death of Castile. He read the complaint against Noor and said he doesn’t believe there is enough probable cause to charge the officer with third-degree murder, “but Freeman obviously had enough to draft a complaint.”

“I’m not privy to what information they have,” he said. “I suspect the lawyers for Noor will bring a motion to dismiss the murder charge because there is nothing in the complaint about him having a depraved mind. He was sitting at the end of a block, got scared and shot somebody.”

Part of Noor’s defense may consist of the fact that Harrity had a better view of the situation and Noor wasn’t in a good position to ascertain the threat level he believed Damond presented, Pacyga said. Nationwide, there had been several instances of police officers being ambushed in their squads around the time of the shooting, he said.

“It’s either shoot or be shot,” he said “You can have all the training you want, but none of it replaces a real-life event. This was very unfortunate, but we don’t have a true appreciation of what Noor was experiencing at the time. That’s what the jury will need to decide.”