The family of a 31-year-old man killed by police last week after an altercation and mental health crisis at an Arby's in Plymouth said Monday they still don't know why the situation escalated.

Derek Wolfsteller of Plymouth was fatally shot Thursday evening by police; he wasn't armed, but, according to a preliminary investigation, he had tried to remove the officer's gun from its holster before the officer fired.

"It was stupid … I realize he was not perfect in every way, but he did not deserve to go that way," said his father, Duane Wolfsteller. "I just don't understand it."

The state Bureau of Criminal Apprehension (BCA) is investigating the incident, which unfolded in less than 20 minutes at an Arby's off Hwy. 55, and will forward its findings to the Hennepin County attorney's office for review when the investigation is done.

It's the sixth reported incident in Minnesota this year of a police officer shooting someone and the third fatality, according to the BCA.

One day before the Plymouth incident, police were called to Wolfsteller's grandparents' home for a mental health crisis, but his father said Monday that police couldn't take him to the hospital against his will.

The next day, Derek Wolfsteller ended up at the Arby's, where he called his grandfather, asking for help, his father said, before calling police with the same request.

Meanwhile, an Arby's employee called 911 about a disturbance and, Duane Wolfsteller said, several restaurant employees tackled his son to the ground.

"He simply asked to be taken to the hospital," Duane Wolfsteller said. "Why it escalated to this point, I don't have a clue. Instead of sending someone to help him with this matter, they sent a female officer who shot and killed him."

The father said the family had long encouraged the 31-year-old to get help, dropping him off at a hospital recently. His son was struggling with depression after his mother's death seven months ago, the elder Wolfsteller added.

"He had so much to look forward to," he said of his son, who he said was close to getting a business degree and loved cooking and snowmobiling. "I just don't get it."

"I wish he had got the help he needed. It's just a tragic accident and situation."

July 23 incident

Additional details about the incident are expected to be released once the investigation is done.

The BCA said that, according to the preliminary investigation, officer Amy Therkelsen responded to a report of a disturbance, and was told on the way that the man had a weapon and was inside the restaurant. When she arrived, two people were attempting to subdue Wolfsteller. When he didn't immediately follow her commands, she used her Taser, but it proved ineffective, investigators said.

According to the BCA, Therkelsen attempted to subdue the man physically, and a fight ensued during which he tried to remove her weapon from its holster. She gained control of her gun and fired at him. No other weapons were recovered from the scene. Another officer arrived just before the shooting, but he and others witnessed it.

Therkelsen, who has been with Plymouth Police for seven years, was placed on standard administrative leave. Ryan Garry, her lawyer, told the Star Tribune last week that "my client acted absolutely appropriately given her training in this life-and-death situation."

Plymouth Police Chief Michael Goldstein said last week that his department had had previous contact with Wolfsteller. He declined to elaborate.

Wolfsteller's criminal history in Minnesota included convictions for drunken driving and other alcohol-related offenses, theft, drug possession and criminal damage to property.

Crisis training

"I don't want to blame the police and I don't want to blame the individual; we need more information," said Sue Abderholden, executive director of the National Alliance on Mental Illness Minnesota. "But we do want to look at this and how can we prevent it in the future."

While Plymouth Police on Monday referred all questions about the incident to the BCA, Deputy Chief Dan Plekkenpol said the department includes mental health training in mandatory training for all staff members.

"We feel quite confident," he said, "we're giving our officers all the training they need."

Kelly Smith • 612-673-4141