Nathaniel Simms, who testified against five other men arrested in a series of shootings in 2010, was sentenced Friday to 60 years in prison, with all but 25 years suspended.
He also received five years supervised release and will be required to make a $5,000 payment to the victims' fund.
Simms pleaded guilty to involvement in the March 2010 shootings -- which occurred on and around South Capitol Street -- a month after they happened. In all, five people died and nine others were wounded in three separate incidents on two different days.
Simms could have received a life sentence.
"I know I played a major part of what was done," he said in court in March 2012. "I expect to spend the majority, if not the rest of my life, in jail."
However, in court Friday, prosecutors said that without his cooperation in these cases, convicting the other five defendants would have been nearly impossible.
During the sentencing, family members of the victims gave impact statements. Simms addressed court as well.
Judge Michael Rankin said he understood the argument made by a victim's mother, who said that a "killer" should not be rewarded even for cooperating with prosecutors.
However, Rankin said that in order to encourage more people to cooperate with police and prosecutors, there has to be something given to those who do. That's why he accepted the government's recommendation of 25 years, he said.
The five other men, who were convicted of multiple felonies, received steeper sentences in September. Three -- Orlando Carter, Robert Bost and Jeffrey Best -- got life in prison without the chance of parole. Another, Sanquan Carter, was sentenced to 54 years. The fifth man, Lamar Williams, received 30 years.
Prosecutors said the violence began over a missing piece of costume jewelry.
The violence culminated in a drive-by shooting on South Capitol Street, where people had gathered following a funeral for another victim killed earlier in the week.
Simms' sentence translates to 10 years each on five counts of murder, and five years each on two counts of conspiracy to commit.
Seth Lemon contributed to this report.