"I already knew what that meant," said Lee, an Army veteran.
Police say the gunman was Mapp's 34-year-old paraplegic brother, who told them that he fired the round after Mapp went on a rampage, attacking their 38-year-old sister, then coming at him. The brother is in a wheelchair because a shooting years ago left him partially paralyzed.
Mapp underwent emergency surgery at the Hospital of the University of Pennsylvania, but was pronounced dead at 6:53 a.m. Hours later, cops were back on the scene, placing markers next to each of his bloodstains.
No charges had been filed as of last night. A police source said it could end up being recorded as a justifiable homicide, but cautioned that the investigation was still ongoing.
"This is a tragedy that's going to rock the family forever," said Lee, who is married to the Mapps' sister.
Neither Lee nor police would release the name of the shooter or the sister, but a source familiar with the case identified them as Jerome Mapp and Deena Mapp. Neighbors on both sides of the street said police have responded to prior disturbances at the house.
Lee said he is close friends with the Mapp brothers, whom he has known for more than 20 years: "We don't say, 'brother-in-law'," Lee said. 'We say, 'brother.' "
Saturday night started off with beers and laughs among Lee, John Mapp and another man, Lee recalled yesterday, wiping away tears with his gray T-shirt.
"You know, sitting on the porch, just laughing, joking, having fun, talking sports," he said. "Eagles, what they're going to do this year. What the Sixers ain't going to do. Next thing I know, John got mad."
It was at that point that Lee went to sleep, he said. Later, he was awakened by commotion downstairs and police coming down the street.
"I couldn't save his life," Lee said of John Mapp.
Lee described the Mapp brothers as "great people" and said they had quarreled in the past, but nothing as severe as what happened yesterday.
"I don't know what transpired," he said.
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