Three teens who laughed as they fatally beat a Starbucks manager on a dare on a Philadelphia subway platform were sentenced Thursday to more than 12 years in prison.

Ameer Best, 18, and 17-year-olds Nashir Fisher and Kinta Stanton joined two others in the five-on-one assault after cutting school in March 2008.

Common Pleas Judge Jeffrey P. Minehart sentenced them each to 12-1/2 to 25 years in prison, concluding the five- to 10-year minimum was "not enough time." He said the crime occurred because no one wanted to be the "punk" who refused the dare.

Sean Conroy, 36, of Philadelphia suffered a fatal asthma attack amid the series of blows. He had found himself cornered and alone on the subway platform near City Hall.

"Sean was my only child. He was my heart, my soul," Sharon Conroy of Lansdowne said, addressing the teens in court.

"I wake up to the sounds of his pleas for mercy, while you laughed," she said, her face lined with grief. "I don't understand how you could laugh. You laughed right up to the time of the verdict."

The group's laughter during the attack drew the attention of a police officer who nabbed Stanton, authorities said. The others were arrested over the next few days.

The midday assault was one in a string of subway attacks that chilled commuters.

Best and Fisher were convicted this year at trial of third-degree murder and conspiracy to commit murder. Stanton was convicted of involuntary manslaughter and the murder conspiracy charge. He alone had been granted a juvenile-court transfer that would have cut his prison time, but the privilege was revoked when he allegedly shot a friend while on house arrest.

Two other co-defendants pleaded guilty and are awaiting sentence.

Families of the three sentenced Wednesday described their sons as "homebodies" who avoided the street. All five defendants attended the same North Philadelphia high school.

Fisher apologized to the Conroy family and said he hopes to become a lawyer.

"This situation changed my whole way of thinking about life," he told the judge. "Most people (in prison) don't got families, like we do."

Sean Conroy volunteered as an after-school mentor in North Philadelphia and took part in food drives, fundraisers and other charitable efforts. He has received several posthumous awards, and a learning center has been named for him at a shelter, his mother said.

His father, Stephen Conroy of West Chester, and Conroy's fiancee also attended the sentencing.