A motorcyclist shot by an Eden Prairie police officer in 2015 says he is suffering from post-traumatic stress disorder and that the injuries he suffered have been "life-altering," according to a federal lawsuit filed Thursday against the officer.

In the lawsuit, filed in U.S. District Court in Minneapolis, Matthew Hovland-Knase, of Bloomington, alleges that Sgt. Lonnie Soppeland violated his Fourth Amendment rights and forced him to endure "pain and mental suffering" during and after the June 20, 2015, traffic stop when he was shot in the left arm "in a situation that clearly did not call for deadly force." Hovland-Knase is seeking $500,000 in compensatory damages. The lawsuit requests a jury trial.

That night, Hovland-Knase, then 21, led police on a 3 a.m. chase that reached speeds of almost 100 miles per hour before stopping at Eden Prairie Road near North and South Lund roads, according to authorities.

In the lawsuit, Hovland-Knase claims that he did not realize the vehicle accelerating behind him was a police car until he noticed the flashing lights reflected from another vehicle. Hovland-Knase then stopped, the suit said.

Soppeland got out of his squad car with his gun drawn — protocol for high-risk stops, he told investigators — but the gun went off, shooting Hovland-Knase in the arm.

According to Hennepin County Sheriff's Office documents obtained by the Star Tribune in January 2016, Soppeland told investigators that recent firearms training had contributed to the unintentional discharge due to a "muscle memory" of squeezing the trigger.

"My plan was to hold the suspect where he was until backup arrived," Soppeland told investigators three days after the incident. " … It was not my conscious choice to discharge my firearm. This all happened very fast, maybe within a matter of a second. I could feel the effect of the adrenaline."

Hovland-Knase's attorney, Robert Bennett, said Friday that the officer did not "accidentally" shoot his client, but did it "voluntarily."

"He did the things necessary to fire a weapon," Bennett said. "You draw the gun, aim the gun at the guy on the motorcycle, then take your finger — which is supposed to be outside the trigger guard, that's how they are all trained — and you fire the gun ... that is not accidental."

According to the lawsuit, Soppeland shot Hovland-Knase "despite the fact that his hands remained visible." Immediately after Hovland-Knase was shot, the officer yelled expletives and told dispatch he had had an "accidental discharge of a weapon."

While tending to Hovland-Knase's wound, the officer told him "it was not intentional by any means ... it still doesn't excuse my actions," then "I'm not going to say any more" as more officers arrived at the scene, according to the lawsuit.

The shooting caused "serious and permanent injuries" to Hovland-Knase's hand and "negatively impacted his job as a warehouse worker, where he was frequently required to lift heavy objects," according to the lawsuit.

Hovland-Knase underwent surgery, physical therapy and "continues to experience significant pain," the suit says. He also received a diagnosis of PTSD, it says.

"The incident has left him fearful and distrustful of police officers," the suit said. "Hovland-Knase has become hypervigilant and easily startled."

After the shooting, Hovland-Knase was convicted of a gross misdemeanor for fleeing an officer. A friend told police that he had borrowed the motorcycle after drinking at Cowboy Jack's in Bloomington. According to the investigation, his blood alcohol content was .05 percent, under the legal driving limit of .08.

Soppeland, who has worked at the Eden Prairie Police Department since 2005, returned to work after being placed on administrative duties during the investigation. Eden Prairie police did not return a call for comment.