Twice since March, prosecutors have tried to convince a D.C. Superior Court jury that Raymond Roseboro was guilty of first-degree murder in the fatal shooting of a 16-year-old. On Tuesday, a jury failed to reach a verdict for the second time.

Judge Thomas J. Motley declared a mistrial Tuesday, the second in the case against Roseboro, after more than four days of deliberations. Roseboro, 21, of Northwest Washington, had been charged in the Nov. 30, 2010, killing of Prince Okorie in the 800 block of Fifth Street NW.

At a preliminary hearing, detectives said they thought Okorie was killed because of rumors circulating in his neighborhood that he was cooperating with police in a murder investigation involving a friend who was charged in the Aug. 22, 2010, killing of Catholic University student Neil Godleski.

That rumor turned out to be false, and prosecutors never identified a motive in the case against Roseboro.

No DNA evidence or murder weapon linked Roseboro to Okorie’s death. Assistant U.S. Attorney Stephen Gripkey, who led both prosecutions, called two witnesses who testified to seeing Roseboro about the time of the shooting, but only one said they saw a gun in his hand. That witness was alone with Okorie in his final hours and was not credible, argued Roseboro’s attorneys James Rudasill Jr. and Anthony Cade.

At the time of the shooting, Rudasill said, Roseboro was coordinating a session with a counselor contracted by the Department of Youth Rehabilitation Services, and the two were still together an hour after Okorie was shot.

Roseboro and the counselor each took the stand in the trial, both testifying that they were with the other at the time of the shooting.

Days into deliberations, the jury began sending notes to the judge saying they were deadlocked. The judge ordered the jury to continue deliberating.

By Tuesday, a final note was sent out, and the judge declared a mistrial and sent the jurors home. In the end, five jurors thought Roseboro was guilty, five voted not guilty and two were undecided.

A hearing was scheduled for Oct. 12, at which point prosecutors will decide whether they plan to seek a third trial or drop the case. Meanwhile, Roseboro remains in the D.C. jail.

“My client is innocent, and hopefully I will be able to better convince a jury if there’s a next time,” Rudasill said.