The suspect has been identifed as 64-year-old William Pulver. He is accused of shooting and killing his neighbor, 65-year-old Patricia Shinn.
It happened just after noon on Tuesday in the 7100 block of Montague Street in Tacony.
Neighbors say they saw the accused shooter pull out a gun during one of the many arguments between him and the victim, but this time it turned deadly.
"They had been going at each other for the last two years, picking, little things but it'll escalate to the point where they're shoving each other," said Annemarie Woltemate.
Witnesses say Pulver was arguing with Shinn in her backyard when people nearby heard gunshots.
Action News has been told Shinn's husband came home with groceries and found her dead.
"We knew it was going to happen, he had a gun. He said it -- verbally threatened her before," Woltemate said.
Police say officers were called to the scene for reports of a neighbor dispute and shots fired.
At the scene, they found Shinn dead from gunshot wounds.
Pulver had apparently gone inside a nearby property and refused to come out when police arrived, leading to officers declaring a barricade situation.
"This is the Philadelphia Police Department, we need you to come to the front door with your hands up," officers could be heard saying. "We know you're in there. We are not going anywhere."
Neighbors described the tense moments as officers blocked off the streets with long guns in hand.
"They told us to get off the porches and get in the house," said Diane Driscoll from Tacony.
"It took about five times, he came out with his hands up, and they put him in a vehicle," Driscoll recalled. "I couldn't believe something like this happened here."
A neighbor recorded cell phone video of Pulver being taken into custody around 1:20 p.m.
"Horrible, horrible. She was such a nice lady. I feel so bad for their family and his family," Woltemate said.
Residents told Action News that the suspect often caused issues with others on the block, including prior arguments with the victim.
"The police were here yesterday, interviewing her. We said, 'He's gonna do something. He's going to shoot her and snap.' I couldn't believe it when I came home from work and found out he did," said Woltemate.
"Yesterday she was on the porch and called the police. They left and today she's gone," added Driscoll.
They also say police have been called to the area more than a handful of times because of the suspect.
Action News has reached out asking police what happened while they were there.
Investigators have not said what led to Tuesday's shooting or what the argument was about.
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