Police gather Tuesday night near Highwood Street in Waterville in response to reports of gunshots in the area. Michael G. Seamans/Morning Sentinel file

WATERVILLE — Police provided more details about the circumstances surrounding the death of a 23-year-old transient whose body was found in the basement of a vacant building Wednesday after an hours-long standoff.

Waterville police Chief Joe Massey said Thursday that the alleged shooter, James Croxford, had a .410 shotgun in his possession, but how he obtained the firearm is still under investigation.

At a media briefing Wednesday, Massey said that Croxford was arrested last fall on an aggravated assault charge. A few weeks ago, he added, an officer had contact with Croxford, but Thursday, Massey said that no charges came from that interaction.

Massey provided more information on events leading up to the standoff.

On Monday, Lynn Berry, who lives next to the 8 Highwood St. building, called 911 at around 2:30 a.m. after she had been woken up by the sounds of windows being broken in the vacant building next door. Massey confirmed that officers were at the scene early Monday morning, but by the time they arrived, no one was in the building. He added that officers did search the entire building, which has three floors and a basement.

“Like most vacant buildings, they are a magnet for vandalism and squatters,” Massey said Thursday.

Bystanders at the scene Tuesday evening claimed an accomplice was arrested. Massey said that an individual was arrested as he would not stay out of the way of law enforcement during the incident. Joshua Thomas, 33, of College Avenue, was arrested on a charge of obstructing government administration after he was asked multiple times to stay outside of the perimeter established by police, Massey said.

Massey said the department is still waiting for confirmation on the cause of death from the state medical examiner’s office.

The Waterville chief said that the investigation was continuing as police try to discover what Croxford was doing prior to Tuesday’s events and anyone who may have had contact with him.

The incident that ended with the discovery of Croxford’s body in the basement of the brick building at 8 Highwood St. broke at 4:15 Tuesday afternoon when Waterville police received several calls about gunshots being fired around 50 College Ave.

The supervisor on duty at the police department suspected the callers may have had the wrong address, so officers were also sent to the area of 150 College Ave. Police converged on College Avenue and cordoned off a large area between Hazelwood Avenue and Highwood Street where the gunshots had reportedly been heard.

Massey said Wednesday that officers heard shots coming from inside a vacant, brick office building at 8 Highwood St., which is across the street from the Mount Saint Joseph nursing home. As officers approached the building, a man later identified as Croxford poked the barrel of a shotgun out of the window.

Just after 4:26 p.m., Lynn Berry, whose house sits next to the brick building, said her Nest camera picked up the sound of gunshots from the rear of the building. The sound of the shots alerted her dogs, Greta and Tucker. Greta was barking out of the windows on the side of the house that faces the brick structure. A moment later, additional gunshots were fired at the Berrys’ residence, almost striking the dog and breaking several windows.

Police retreated and called for more units to set up the perimeter. Around 6:30 p.m. Tuesday, officers heard two final shots come from inside of the building.

Police did not enter the building until just before 4 a.m. on Wednesday when a tactical team large enough to cover the entire building was put together. Croxford was found dead in the basement of the building with the firearm near him.

Massey said Wednesday that about 50 officers were at the scene helping out. Around 25 nearby residents, most from the Home Place Inn, had been relocated for the evening as the situation unfolded. Included in that number were families and children as well as some who had medical issues and needed to stay at the hospital to receive medication.

The Waterville department was assisted by Maine State Police, Fairfield, Oakland, Winslow and Clinton police departments, U.S. Department of Homeland Security, Waterville Fire and Rescue, and Delta Ambulance.

“This was a very tragic event for this young man that ended up dying,” Massey said Thursday.

Attempts to make contact with relatives of Croxford were not successful Thursday.