OLD TOWN — A Maine State Police trooper shot and killed a man who reportedly stabbed his girlfriend to death Wednesday night in a downtown apartment.

Police identified the couple on Thursday morning as April Haskell, 35, and Christopher Ouellette, 28, both from the Old Town area, according to Maine Department of Public Safety spokesman Stephen McCausland.

They are believed to have lived in the apartment for about two months.

Two children, ages 2 and 4, were in the third-floor apartment during the incident and were unharmed. The children have been placed in the custody of relatives.

Autopsies are scheduled Thursday at the state medical examiner’s office in Augusta.

According to McCausland, police went to the area around 6 p.m. after Ouellette called police to say he had stabbed his girlfriend.

Col. Robert William, chief of the Maine State Police, said at the scene that the trooper involved in the shooting is Barry Meserve, a 15-year veteran, McCausland said.

As is standard procedure, Meserve has been placed on administrative leave with pay as state police and the Maine attorney general’s office investigate the incident.

The Maine State Police mobile crime lab, several ambulances and police from several municipal departments were at the scene for several hours. Several blocks around the scene were still closed late Wednesday night.

People in the neighborhood said there was an armed man in an apartment above the Subway near Middle and Main streets and that the building was evacuated. What sounded like several rounds of gunfire was heard in the area around 6:40 p.m.

Scott Morrison, 42, a former U.S. Army infantryman who lives in Old Town and was near the scene of the standoff, heard five shots. The first one was either a high-powered rifle or a shotgun he said, and the next four were pistol shots.

This story was updated at 9:25 a.m.