James Elijah Dickson, 46, of the 600 block of East Westmoreland Street, was taken into custody after a standoff with police.
According to authorities, there were five people inside the home when an argument broke out when Dickson pulled out a shotgun and opened fire.
The dead include Dickson's brother, his brother's girlfriend, and another man.
Police say the fourth victim was shot in the arm and was able to run away. He was found on the 500 block of East Westmoreland Street and taken to Temple University Hospital with non-life-threatening injuries.
Investigators say Dickson called 911 just before 4 a.m. and told the operator about the shooting.
PHOTOS: Deadly shooting in Kensington
When officers arrived at the home, they say Dickson refused to leave.
"He indicated that he was not about to open the door and allow the police inside. At that point, the 25th District personnel declared a barricaded situation," said Philadelphia Police Chief Inspector Joe Sullivan.
Police called in SWAT teams and other officers, but still the suspect remained in the home.
A homicide detective trained in hostage negations was able to connect with the suspect on the phone. Police tell Action News the detective spoke with Dickson for approximately two hours before the man ended the call.
Police say when the SWAT team climbed on the roof of the home, the suspect fired shots at them.
Shortly after that, police say Dickson came out through the front door and they were able to take him into custody.
A weapon was recovered from the home.
Neighbor Leslie Suarez said she is friends with the suspect and police told her he asked to speak with her before he surrendered.
"He sent the cops to look for me because he wanted to talk to me. He wanted to give up, but he wanted to see me first. I don't know what he was going to tell me. Police said they used me to take him out. They told him they were going to get me. And police knocked on the door and that's when he opened the door," Suarez said.
Suarez tells Action News the suspect struggled with stress and anger, and about a month ago he broke a window in his home. But she says she never thought he was capable of anything like this.
"I wanted to talk to him. I wanted to see what he was going to tell me," said Suarez. "Maybe he was going to tell me the story, that he was innocent or something."