They surrounded and combed each floor of the building, even perched on the roof next door, until they yanked out a man in handcuffs.
The victim's family members say 36-year old Michael Taffe was fed up with tenants doing drugs in his mother's backyard.
The confrontation, his mother says, cost him his life.
"They said the guy downstairs shot him and that guy was doing marijuana. So my son pulled the hose. I guess he called up his friend and they shot him," Dolores Facey said.
Family members say Taffe used the hose to wash the drugs down the drain.
The suspects shot Taffe six times in the back, police said.
The murder happened around 10:00 Thursday morning at the home off Barnes Avenue.
Police confirm Taffe got into a dispute with a large group of men.
Witnesses say as many as five men took off running after the shooting.
Police put several people into police cars at the scene, but they have not announced any arrests.
"I hope they catch the person who did this and I hope he pays for what he did," the victim's sister, Lola Facey, said.
"I can't believe somebody would kill Mikey," Iota Thomas, a family friend, said. "It's a loss."