Kevin Cullen had long battled his internal demons, struggling with alcohol and living a transient life around Mayfair. His family acknowledges that.

But they didn't expect the 57-year-old's life to end as it did this week, when a group of teens allegedly beat him on a sidewalk around the corner from his childhood home, emptying his pockets and leaving him for dead.

"He'd be somebody you'd see on the street all the time, and maybe you'd help him out, maybe you wouldn't," said his younger brother Mark, 54, who slept on the bunk bed beneath Kevin growing up. "But he wasn't aggressive or mean or any of those things."

Police say Kevin Cullen died Monday morning at Jefferson Torresdale Hospital, about 13 hours after he was attacked on the 4200 block of Loring Street, near where the Northeast Philadelphia neighborhoods of Holmesburg and Mayfair meet.

Detectives on Tuesday were still investigating, and no arrests had been made. Homicide Capt. John Ryan said that two people had been taken in for questioning but were released pending additional investigation.

Police said only that the teens had been wearing dark clothing and that one had been seen in a gray camouflage jacket. Robbery was the motive.

Tom Cullen, the oldest of Kevin's five siblings, said his brother probably had nothing worth stealing. Kevin had worked a variety of jobs during a prolonged battle with alcohol addiction, he said, but was a "fixture" in the neighborhood whom residents often tried to help out.

He loved rock music, Tom said, bands with big guitar sounds like Kiss and the Who.

He graduated from Father Judge High School in 1979, said his brother Mark, and was intelligent and funny even through his ups and downs.

A vigil is planned for 6 p.m. Wednesday on the block where he died. In the meantime, Mark Cullen said, family members were still trying to come to grips with their brother's violent death.

"It's going to haunt me for a long time," he said.

Staff writer Joseph A. Gambardello contributed to this article.