An apartment complex in Albert Lea became the scene of three investigations on Sunday: that of an active shooter, an officer who fired a gun and an unrelated death.

A suspect who barricaded himself in an apartment was arrested just before 11 a.m. Sunday, about nine hours after authorities say he shot a police officer and two other men.

During the incident, a Minnesota State Patrol officer discharged a gun. As of Sunday night, it was unknown if the suspect was shot, but he was injured by shrapnel and was taken to a Rochester hospital, according to the Minnesota Bureau of Criminal Apprehension (BCA).

The Star Tribune generally does not name suspects until they've been charged. Authorities said the suspect is 21 and from Albert Lea.

As authorities were evacuating the apartment complex on the 800 block of S. 4th Avenue, they found a body. Albert Lea police are investigating the death, which they say is unrelated to the shootings. The remains have been taken to the Ramsey County Medical Examiner's Office for identification and to determine the cause of death.

J.D. Carlson, the city's director of public safety, said the active shooter suspect barricaded himself inside the apartment for hours while police asked people to avoid the area and shelter in place.

Carlson said the initial 911 call was a "typical noise complaint."

The officer was shot multiple times and was hit once in the chest but was able to drive to an emergency room, police said. He was wearing a protective vest, according to the BCA.

"Essentially, in my opinion, it was an ambush situation," Carlson said, adding that the officer was treated and released. The identity of the officer, who is 30, was not released.

Two men, ages 52 and 38, were also shot and taken by air ambulance to a hospital in Rochester to be treated for noncritical injuries, according to the BCA.

The suspect's mother told the Star Tribune that she saw no warning signs and described her son as kind and helpful.

The BCA will release any additional information once initial interviews are complete.