Two women and a man were shot to death inside a house in central Maine, and the gunman's body was found outside, police said early Thursday.

Officials received a number of 911 calls reporting a shooting at a home in Oakland at about 8 p.m. Wednesday, Department of Public Safety spokesman Steve McCausland said in a statement. He said one of the calls came from one of the women who had been shot and later died.

The three victims and the gunman shared the home, which was divided into two apartments, McCausland said. The victims were found dead in one of the apartments, while the gunman was found in the driveway with a gun next to him, he said.

A 4-year-old girl was found unharmed inside the house. The girl has been turned over to relatives, officials said.

The three victims were identified as Amanda Bragg, 30; Michael Muzerolle, 29; and Amy Derosby, 28. The gunman was identified as 42-year-old Herman Derico.

Police said Bragg and Muzerolle were the parents of the 4-year-old.

Investigators are trying to determine a motive. McCausland said detectives will talk to family and friends to try to understand what happened.

"The main focus is on why this violence took place. At this point in the investigation, we don't have an answer," he said.

Maine State Police Lt. Troy Gardner said all four individuals died from gunshot wounds. He said police believe Derico shot all three victims before turning the gun on himself.

“It’s obviously a terrible crime,” Oakland Police Chief Mike Tracy said.

The Portland Press Herald reports six law enforcement agencies responded to the scene after the report of the shooting and at least 15 police cruisers pulled up to the house shortly after 8 p.m. Police blocked off the area around Belgrade Road, where the house is located.

Neighbors around the area told the Press Herald the area is usually quiet. Multiple neighbors told the newspaper they didn’t hear gunshots, just sirens.

The Associated Press contributed to this report.

Click for more from The Portland Press Herald.