Six months after the seemingly random murder of a 12-year-old boy in East Baltimore, police had not been able to solve the case, and, a prosecutor said in court Tuesday, the investigation had "gone cold."
But then in December 2011, a defendant in a drug case told prosecutors he knew something about the killing. Antwan Mosley told them that the boy, Sean Johnson, was gunned down as members of the Black Guerrilla Family gang lashed out in revenge for an attack on of one of their own.
"That was a key break in a tragic homicide," Assistant State's Attorney Kelly Madigan said.
Although Mosley, 23, did not take part in the shooting — which also left three other boys injured — and worked extensively with authorities, he was charged with conspiracy to commit murder for his role in the attack. He pleaded guilty to that charge and Circuit Judge Martin P. Welch sentenced him Tuesday to 15 years in prison.
But the sentence was at the low end of what Mosley agreed with the state's attorney's office, and it was handed down at the end of an unusual hearing in which both the prosecutor and judge praised the defendant.
Madigan spoke of Mosley's courage for cooperating with authorities as they prosecuted the two other men who had fired the shots.
"He was 100 percent honest and remorseful," Madigan said of Mosley. "He did everything the state could ask of a cooperator."
After hearing more than a full day of testimony from Mosley, a jury convicted Danyae Robinson, 31, and Derrick Brown, 20, last month of conspiracy to commit murder, murder, attempted murder and gun offenses. The two men, members of the BGF, brought Mosley along the evening of the killing to help identify a man known as "Critic," whom they suspected of shooting another member of their gang.
Unable to find their target but still wanting to a send a message to the neighborhood, prosecutors said, Robinson and Brown opened fire on Johnson and three other boys. They were sitting on their porch and watching a televised basketball game when the two men fired at least 15 times.
In his comments to the judge Mosley said he had "great remorse" for what happened.
"If I could go back and do the day over, I would probably have tried to do anything to stop the events from taking place," he said. "I would like to — on the record — apologize to the kid's family because I never got the chance to do that."
Welch said that Mosley's words showed wisdom beyond his years, a trait not shown by many of the defendants he sentences.
Ivan J. Bates, Mosley's attorney, said his client decided to come forward after becoming a father himself.
"What changed in Antwan's life is when he had two twins of his own," Bates told the judge, "and that he felt a lot of guilt and remorse because a 12-year-old had been shot and killed."
But in an interview, Brown's attorney, Russell A. Neverdon Sr., questioned Mosley's motivation for working with prosecutors.
"It was clearly about what was in his best interest," Neverdon said. "He availed himself of the system."
Neverdon, who is running for state's attorney as an independent, also questioned the wisdom of offering Mosley such a lenient sentence. Both his client and Robinson face multiple life terms at their sentencings next month.