The house wasn't known as drug den, police say, but 2 victims were dealers.
Seven people killed in a run-down row house had been lined up on the dining room floor and shot by four masked intruders, police said Friday.
Six men and one woman were killed Thursday night. Three other people were wounded, and two remained hospitalized Friday.
"We know that a robbery occurred inside, but it would seem to me that you don't slaughter 10 people for a few bucks," Capt. James Brady said. "So I think there's a deeper motive involved than a single, straight-up robbery."
Brady said police had no suspects. He also said the home did not have a history of being a drug den.
Police said two of the victims had recently begun selling drugs, and a small amount of crack cocaine was found in the house, situated in a crime-ridden neighborhood amid homes with boarded-up windows, fallen awnings and overgrown lawns littered with fallen bricks. It is not far from a school.
"Every house on this street is abandoned. They should knock them down and give the neighbors support," said Steve Hawkins, a community activist.
It was the nation's second shooting in two days to claim seven lives. On Tuesday, seven people were slain at an Internet company in Massachusetts, allegedly by a co-worker.
Police in Philadelphia said the victims ranged in age from 15 to 44, with one still to be identified.
Survivors of the shooting told police that four people wearing masks broke into the house just after 8 p.m., Brady said.
One woman said she heard a woman inside the house scream, "Help me! Oh my God, help me!" during the shooting. Neighbors who gathered afterward asked police to see if family members were inside.
"I want to go in there!" one woman shouted, according to the Philadelphia Daily News. "My baby's in there!"
Another woman was singing, "Jesus wants me. . . ."
"The same scenario is played out every day _ crack house, school. Crack house, church. Crack house, neighborhood," said Malik Aziz of the community organization Philadelphia Making a Difference Against Guns, Drugs and Violence.
Charles Williams, 38, said the neighborhood was rife with drugs.
"It's been like that for many years. There's a lot of young kids around here, shooting late at night."
AP Officers scour the scene of Thursday's shootings in a row house that claimed victims ranging in age from 15 to 44, with one still to be identified.