A grand jury has indicted a sheriff's deputy on a charge of second-degree manslaughter in connection with the 2018 shooting death of a 23-year-old Lake Elmo man.

He's the state's third law enforcement officer in recent memory to be charged in an on-duty killing.

The indictment was returned Friday against Brian Krook, 31, who shot Benjamin W. Evans shortly after midnight on April 12, 2018, while Washington County deputies were responding to a 911 call of a suicidal man in Lake Elmo.

Tenth District Judge Doug Meslow said Monday that the charge states Krook acted with "culpable negligence," created an unreasonable risk and consciously took "chances of causing death or great bodily harm to another."

The other cases of officers charged in an on-duty killing both involved deaths in the past three years. St. Anthony police officer Jeronimo Yanez was charged with second-degree manslaughter and acquitted by a jury in the July 2016 killing of Philando Castile, and ­Minneapolis police officer Mohamed Noor was charged and convicted of third-degree murder in the July 2017 shooting of Justine Ruszczyk Damond.

Krook remains free ahead of his first court appearance, which has yet to be scheduled, Meslow said. Krook did not return a message left at his home seeking comment.

The specifics behind the indictment have yet to be released by prosecutors for the Ramsey County Attorney's Office, which is handling the case to avoid a conflict of interest in Washington County.

An attorney for Evans' family said they have been kept largely in the dark about his death and have yet to see the charging document.

"There's not much we can say about the indictment," said attorney Peter Sandberg, who added that prosecutors told him about it Friday and that he was not expecting it to be made public for several business days afterward. "We have little or no details about what happened in April 2018."

Disclosure of the indictment came on the same day that Minnesota Attorney General Keith Ellison and state Department of Public Safety Director John Harrington announced formation of a working group that will focus on officer-involved shootings.

It also comes as law enforcement and the state look for ways to reform how police handle encounters with people with mental illness. At least 45 percent of the people who have died in forceful encounters with law enforcement in Minnesota since 2000 had a history of mental illness or were in the throes of a mental health crisis, according to a Star Tribune analysis.

According to the state Bureau of Criminal Apprehension (BCA), deputies made contact with Evans near 34th Street and Lake Elmo Avenue, close to his home, as he held a gun and told officers he wanted to kill himself.

Officers made repeated attempts to persuade him to put down the gun, the BCA said. At some point, Krook fired at Evans, striking him multiple times.

Deputies provided medical aid to Evans before he was taken by ambulance to Regions Hospital, where he died.

The BCA said a handgun was recovered near Evans' body. A law enforcement beanbag shotgun also was recovered, but it did not appear to have been fired.

Body cameras and squad car dash cameras captured portions of the incident, the agency added.

Evans had completed his studies to be a firefighter and was working as an emergency medical technician at the time of his death, the family attorneys said. Among his survivors is a 3-year-old daughter.

One of the attorneys, Elham Haddon, said Evans' family members are still "trying to get their heads around this. Ben was a public servant … and a stellar human being, and they want to know why this happened."

Haddon said she was unable to find even a traffic ticket on his record, adding, "He has a rap sheet that reads like a blank sheet of paper."

The attorney said that Evans had been having emotional difficulties, "and it had a lot to do with his love life."

Evans moved from the St. Louis area to Wabasha about nine months ago to be with his girlfriend before moving on his own to Lake Elmo, Haddon said.

At the time of the shooting, the American Civil Liberties Union's Minnesota office released a statement calling for better training for law enforcement in dealing with people in a mental health emergency.

"We shouldn't have to wait for police to kill another person in crisis to see meaningful reform," the statement said.

Three public hearings by Ellison and Harrington's group are planned. A final report to the Legislature is expected by February 2020.

Krook was an eight-year veteran of the Sheriff's Office at the time of the shooting. He was briefly put on paid administrative leave after the shooting, returned to duty and went back on the same leave status Monday, the Sheriff's Office said. It did not explain the reason for the latest change in status.

Krook received a lifesaving award with a fellow deputy for their actions on Christmas Day 2012 to revive someone in Lake Elmo who was unconscious and not breathing.

Paul Walsh • 612-673-4482