A Maine State Police evidence processing van is parked Thursday morning outside a building at Oxford and River streets in Lewiston after a shooting Wednesday night. Daryn Slover/Sun Journal

LEWISTON — The killing of a man Wednesday night on River Street was declared a homicide Thursday.

An autopsy was conducted Thursday afternoon on the man found dead at 53 River St. Beyond that, police did not release other details, including cause of death and the identity of the victim.

Witnesses close to the situation said the deceased is a man in his 30s who has a criminal history involving drug offenses. A neighbor said she is familiar with the victim, but was not sure if he had been living on River Street.

The man described as a possible suspect was said to be on the run Thursday afternoon.

The investigation into the killing was ongoing Thursday night with Maine State Police heading it. Lewiston police had responded to the home for a reported robbery Wednesday night although some people familiar with the scene described it as a home invasion.

“Major Crimes Unit detectives and members of the Maine State Police Evidence Response Team have been on scene all day interviewing witnesses and processing the scene,” according to State Police spokeswoman Shannon Moss. “Investigators are currently working with local, state and federal partners to investigate this crime. Detectives do not believe there is a threat to the public. ”

A Lewiston police officer operates a drone Thursday morning over a building at Oxford and River streets. Police surrounded the building overnight after reports of gunfire. Daryn Slover/Sun Journal

Police surrounded the home at the end of River Street on Wednesday night shortly after shots were reportedly fired in the area.

Shortly after 7 p.m., residents near the intersection of River and Oxford streets reported hearing gunfire, according to witnesses at the scene. A short time later, police swarmed the area and quickly began evacuating two floors at 171 Oxford St., near the end of River Street.

A witness said a group of young adults was in the area shortly before shots rang out. Once shots were fired, those youths fled and a car was seen speeding away from the scene. Police did not comment on those elements on Thursday.

One woman who lives near the scene said she wanted to flee the area with her children as police began to arrive. Shortly after, though, she was told to stay inside her home and the streets were blocked.

While the standoff was underway on River Street, Lewiston police were called to a second location on Lorraine Avenue where a man was reported to be holed up in his home and refusing to come out. He came out without incident a short time later. Police said that situation was not related to the events on River Street.