Gang member Lamar Blackwell was sentenced to life in prison plus 18 years as a habitual offender for killing a man who was wearing the wrong-colored shirt at a hip-hop club.

Blackwell, 29, was convicted of first-degree murder in the shooting of 22-year-old Jerome Martin. During the trial, prosecutors said Blackwell shot Martin in the back because he believed the victim had disrespected Blackwell's Crips gang, stepped on his shoes and was wearing a red or maroon shirt. Those colors are associated with the rival Bloods gang.

"His response is to senselessly gun down this young man in the prime of his life for absolutely no reason at all," said prosecutor Tim Twining. "This was gang-fueled outrageous nonsense."

Martin's mother said she really doesn't know why it happened.

During the trial, Blackwell's defense attorney said he had just fired a couple of shots into the air, although Cleus Williams, who was with Blackwell at the club, testified that Blackwell told him he was going to "merc this fool," meaning he was going to kill him.

The shooting took place in a 16th Street Mall parking lot as Martin was leaving a hip-hop party at Club Beyond on April 5.

"It was senseless," Charlene Martin said. "There was no reason for it. But what angers me the most is he chose not to speak to police or anyone. So I don't know why he did it. That's the hardest part."

Martin said her son was working, going to college and had his own place. "He was being responsible. He did everything he had to do."

She said his death devastated her family. Jerome Martin's grandfather, who helped raise him, died of a heart attack several months after his grandson was killed. Jerome Martin's grandmother suffered a heart attack during the trial in January, she said.

"This has affected all of us," she said.

She and other family members did not speak at the hearing in Denver District Court, but sent letters to the judge. She said Blackwell received the sentence he deserves.

"Justice has taken place and he has received a sentence to keep him off the streets for the rest of his life," she said.

Blackwell was classified as a habitual offender because of previous convictions in a 1998 drug case and a 2000 federal conviction as a felon in possession of a firearm. That led to an additional sentence of 18 years in prison for vehicular eluding.

After gunning down Martin, Blackwell led "scores" of police cars on a wild chase that ended when he slammed his black Chevrolet Suburban into a police vehicle, Twining said.

Denver District Judge John Madden IV told Blackwell his "spur of the moment" bad decision destroyed his life as well as Martin's.

"In the end, this is a tragedy for everyone involved," he said.