The man shot and killed by a St. Paul police officer Saturday night inside an apartment complex had been behaving erratically while fellow residents in the building held a gathering, residents and acquaintances said Sunday.

An officer fatally shot the man after he "advanced" toward them, a spokesman for the St. Paul Police Department said a few hours after the shooting. The Minnesota Bureau of Criminal Apprehension is investigating what happened, and a spokeswoman said Sunday that additional details would not be released until Monday.

The incident occurred about 5 p.m. Saturday after police said the man was asked to leave a group event in an apartment complex community room. Calls came in to police shortly after about an older man with a knife who was seen in different parts of the complex on the 100 block of Western Avenue S.

Holding a knife, the man advanced toward police officers when they found him in a first-floor hallway of the complex, said Sgt. Mike Ernster, the St. Paul police spokesman.

"Officers attempted to get him to drop the knife," Ernster said. "The officers retreated as the man advanced toward them. One officer deployed a Taser, and another fired shots at the man," Ernster said at a media briefing just before 11 p.m. Saturday.

Resuscitation efforts by St. Paul Fire Department medics were unsuccessful, and the man was pronounced dead at the scene.

Ernster said the identities of people involved in the incident and other details will need to come from the BCA.

The apartment complex, known as Winslow Commons, is privately owned and offers Section 8 housing for people age 62 and older. Neighbors said some of the residents receive disability benefits for mental health difficulties.

Neighbor Mark Ritter said he got to know the man who was shot in recent weeks when they went outside to smoke late at night, though he did not know the man's name. Ritter said his late neighbor was polite, always helpful lighting a cigarette or holding the door.

"I've never seen any aggression out of him," Ritter said.

Ritter and another neighbor said the man killed by police was an older Asian man who spoke limited English. Ritter said he understood the man had fought with Americans during the Vietnam war but cautioned there had been a language barrier between them.

Other neighbors were having a gathering in a community room near the man's apartment. One resident, who said he witnessed the shooting but who did not wish to be identified because he worried about losing his apartment, said the man wanted the gathering to break up because he wanted to sleep. He was holding a large kitchen knife, the neighbor said.

Ernster said all officers involved will be placed on administrative leave, per department policy. The officers were wearing active body cameras that will be used as part of the BCA investigation.

More than 220 officer-involved shootings have occurred in Minnesota since 2000, including at least 30 in St. Paul. The most recent incident on Dec. 14 involved a 34-year-old man who was shot and killed in New Auburn, Minn., when he reportedly used a knife to fight with police officers who were sent to check on his mental welfare.

St. Paul police shot a 24-year-old man on Dec. 4 who authorities said was armed with a gun.

Reporter Dave Orrick contributed to this report.

Correction: The photo caption has been corrected. The image was provided by Mark Ritter.