Mohamed Noor was arrested by the Hennepin County Sheriff's Office in the death of Justine Damond, 40. His bail was set at $500,000, according to county jail records.

The third-degree murder charge accused Noor of committing an "eminently dangerous act" and showing a "depraved mind," and the second-degree manslaughter charge cited "culpable negligence creating unreasonable risk," the records showed.

The penalty for third-degree murder is up to 25 years in prison and second-degree manslaughter carries a penalty of up to 10 years, according to a state website. 

Minneapolis' top prosecutor Hennepin County Attorney Mike Freeman is expected to announce the charges at a news conference at 2:30 p.m. local time in the July 2017 death of Damond, who was shot by Noor from his patrol car.

Freeman had delayed his decision in December, saying his office needed more time and he did not have enough evidence to charge Noor. The county attorney's office declined to comment beyond the statement on Tuesday.

Noor has been on paid leave and had declined to be interviewed by Minnesota state investigators. Neither Noor's attorney, Tom Plunkett, nor the head of the Minneapolis Police Union, Bob Kroll, could immediately be reached for comment.

Plunkett has said that Noor extended his "thoughts and wishes" to Damond's family and raised concerns about Freeman's objectivity. 

The attorney for Damond's family, Bob Bennett, could not be reached on Tuesday.

Damond's fiance Don Damond, and her father, John Ruszczyk, issued a joint statement in which they praised the decision to charge Noor and hoped it resulted in a conviction, according to the Minneapolis Star Tribune.

"No charges can bring our Justine back. However, justice demands accountability for those responsible for recklessly killing the fellow citizens they are sworn to protect," they said in the statement, according to the newspaper report.

Damond, who was living in Minneapolis and engaged to be married, had called police about a possible sexual assault near her house and approached the police after their arrival, authorities have said. She had owned a meditation and life-coaching company.

The shooting drew condemnation in Minnesota and Australia, where Prime Minister Malcolm Turnbull called it "shocking" and "inexplicable." Then-Minneapolis police chief Jamee Harteau resigned after city officials said procedures had been violated and Damond "didn't have to die."

Neither Noor, who came to the United States from Somalia as a child, nor Matthew Harrity, another officer in the patrol car, had their body cameras activated, police have said.

Harrity told investigators he was startled by a loud sound near the patrol car shortly before Noor fired. Court documents said a woman slapped the back of the car before the shooting.