MINNEAPOLIS (WCCO) – Police in St. Paul are looking for information that can help them piece together what happened Monday moments before officers opened fire on an armed man.

Police responded to the 400 block of White Bear Avenue that afternoon on reports of an armed man wearing a bulletproof vest, screaming incoherently around the neighborhood. Officers ended up shooting and killing the man.

On Tuesday, investigators were going door to door, asking people what they knew about the suspect. Police later identified him as 28-year-old Justin Todd Tolkinen, of St. Paul.

An aunt and uncle of Tolkinen’s laid flowers at the scene of the shooting. They did not want to talk on camera, instead they stood holding each other at the spot their nephew took his last breath.

Investigators spent most of the night and part of the day re-interviewing neighbors and witnesses, trying to determine what led up to the shooting.

“This is a puzzle we put together by the corners, and we fill in the middle. That’s what we’re doing right now,” said Sgt. Paul Paulos.

What police do know is they were called to the area Monday on reports of a man wearing a bulletproof vest, carrying an automatic weapon.

“We heard someone screaming outside, and he was waiving his AR around in the air,” neighbor Jade Decora said.

Witnesses say Tolkinen was screaming and eventually went back inside the house, taking the automatic weapon with him.

When police arrived, neighbors say there was an hour-long standoff that ended with a confrontation between Tolkinen and a SWAT team.

Police say they tried to take Tolkinen into custody without seriously injuring him.

“We used non-lethal on him at the first round,” Paulos said. “That failed. It was followed up by lethal force, which was the shots fired by the officers and he died on the scene.”

Investigators have lots to figure out.

Right now, it is unclear who fired first, or if Tolkinen fired his weapon at all.

Police say they are trying to figure out what Tolkinen was saying at the time of the shooting and what he was doing before he was shot.

Four officers were placed on administrative leave for their role in the shooting, which is standard procedure whenever an officer discharges a weapon.

The officers were identified as Mark Farrington, Brian Hall, Patrick Murphy and Jermaine Davis.

Reg Chapman