Updated 12:50 p.m. | Posted 12:10 p.m.
The Hennepin County Sheriff's Office is investigating how the man who shot up New Hope City Hall Monday and wounded two police officers obtained a firearm.
Raymond Kmetz, 68, was prohibited by state law from having the pistol-grip shotgun he used in the shooting, Hennepin County Sheriff Rich Stanek said Wednesday.
Kmetz had been in and out of the Minnesota Security Hospital in St. Peter and an Anoka mental hospital and so should not have been able to possess the weapon.
"He is a prohibited person under Minnesota state law, so he should not have had access," said Stanek, who asked for patience as the department investigates the circumstances surrounding the shooting.
"We do not know how he obtained that firearm, we do know that he made a stop earlier in the day at a store and purchased ammunition for that shotgun," he added.
Kmetz began firing at police officers as they left the council chambers following a swearing in ceremony for new officers, officials said. Police returned fire, killing Kmetz.
"There's still a great deal of work to do and there are still many unanswered questions," Stanek said, adding that findings will go to the Hennepin County Attorney's Office for review.
The two injured New Hope police officers, Joshua Eernisse and Beau Schoenhard, both received medical treatment for non-life threatening injuries and are doing well, the sheriff's department reported.
• Tuesday: New Hope City Hall gunman had troubled past
New Hope Police Chief Tim Fournier described officers involved in the incident as heroes.
"This happened very fast, the officers acted as they should, as is their training," he said. "They took down the threat, they protected the environment and protected the building."
Kmetz's brother, who asked that his first name not be used, told MPR News earlier in the week that Kmetz had developed delusions that he was being persecuted by law enforcement and government officials after his landscaping business closed during the recession.
Court records show that Kmetz had a history of confronting government and the law, including an incident where he allegedly turned a bulldozer on an officer. He'd also been arrested for incidents including assault, stalking, making terroristic threats, burglary and property damage. The city of Crystal asked for a restraining order against Kmetz last year.
Police records show that Kmetz's family had warned police in Crystal that he'd threatened to bring a shotgun to the city to retrieve property he believed officials had taken.
Kmetz had been committed to state mental health treatment years before, although he'd been released from the state hospital in St. Peter in 2013.
Minnesota state law forbids people from possessing firearms if they've ever been committed to an institution after a finding of mental illness.