Brian Hardison held up a photo of his only son Evan for the whole courtroom to see Tuesday. The smiling face of a brown-haired teen with sparkling green eyes stared out from the frame.

Hardison then held up a second shot of Evan lying comatose in a hospital bed after a potent dose of heroin.

"This didn't have to happen," Hardison said, hoisting a third photo of the Mount Pleasant teen's pale and emaciated body two hours after his November 2007 death.

A federal judge agreed and sentenced the dealer who sold that fatal batch of heroin to 27 years in prison for peddling the drug on Charleston's streets. The dealer, Nathaniel Colleton, had previously pleaded guilty to three drug counts in the case.

Colleton's family and friends packed the courtroom to show their support for the 26-year-old father of two, who had no prior convictions. His uncle described him as a promising young man with a "godly heart." And after his attorney, Dale Cobb, asked for leniency, family members detailed Colleton's solid upbringing, his musical talents and his compassion for others.

U.S. District Judge David Norton, however, said he was at a loss to understand how Colleton could have continued selling heroin while knowing someone had died from the drugs he peddled. Colleton was free on bail on charges related to 18-year-old Evan Hardison's death when he was busted a second time for selling heroin to a police informant in August 2009.

"I don't understand that at all," Norton said.

Assistant U.S. Attorney Peter Phillips said the second arrest showed Colleton's "callousness and lack of remorse beyond what anyone can say."

Speaking in a hushed tone, Colleton mumbled a brief apology to the court, his relatives and Hardison's family. He stared straight ahead while doing so, never turning to face the assembled crowd.

During his earlier plea, Colleton acknowledged conspiring to peddle more than 100 grams of heroin and selling the batch that killed Evan Hardison.

Hardison was found unresponsive the morning after he tried heroin for the first time at a party in Mount Pleasant's Oakhaven Plantation on Oct. 22, 2007. The episode left him with severe brain damage, and Hardison died at a hospice facility the following month.

His father told the court that Evan made a fatal mistake that night, but he was a good, hard-working, compassionate teen who came from a loving family, as had Colleton. "Neither one of these kids grew up in bad homes," he said. "They both knew better than this."

Brian Hardison said his son's death has robbed him of a friend, future grandchildren and many years of memories yet to be made. Still, he said he would not carry hatred in his heart for Colleton.

"You are forgiven, but you need to be punished," he said, staring straight at Colleton. "I feel bad that your family will lose contact with you. But my son is dead."

The Rev. Kay Colleton, the defendant's mother, said justice should be spread around in the case and encompass all who were using drugs the night Evan Hardison died. She said police should have charged the girl who hosted the party and distributed the drugs to Evan. Those who left him unresponsive in his car down the street to deflect attention from themselves also should be held accountable, she said.

Phillips told the judge that Mount Pleasant police investigated those aspects of the case and consulted with the solicitor's office, but county prosecutors found there were no appropriate charges to bring.

Federal prosecutors went after Colleton with the so-called "Len Bias law," aimed at dealers whose sales lead to grave injury or death. The law is named after a University of Maryland basketball standout who died from a cocaine overdose just days after being drafted by the Boston Celtics in 1986.