PHILADELPHIA (CBS) — Three people are dead after a shooting and violent standoff in Kensington early Sunday morning.

Authorities say the saga began around 3:45 a.m. when they received a 911 call about a man shot in the arm in the 500 block of East Westmoreland Street. Police found the victim and took him to the hospital.

More 911 calls began to come in a short time later about a shooting inside 637 East Westmoreland Street.

When officers arrived at the home, a man inside refused to open the door for police. He yelled that he had a shotgun, and told police he had shot someone and was not coming out.

Police declared a barricade and SWAT teams were called to the scene.

Authorities say when SWAT units climbed on top of the roof, the suspect, who was known to police, fired several shots at them, but they were able to talk him down and take him into custody.

“Hostage negotiators went down to police radio to assist the sergeant in the peaceful surrender of this male,” said Chief Inspector Joe Sullivan.

When police opened the door, they discovered a tragic scene inside. Police say a man in the living room had been shot in the head with a shotgun. Another man was found lying face down on the dining room floor with a shotgun wound to the back of his head, and a woman was found lying on the floor of the kitchen. She had also been shot in the head with a shotgun.

All three victims inside the house were pronounced dead at the scene.

“He just moved around here,” said neighbor Tamikia Johnson. “I’m shaking on the inside. I am really scared to wake up to something like this.”

There was no initial word on a motive for the shooting. Police continue to investigate.