Lawyers for John Giuca, a Brooklyn man convicted more than a decade ago of murdering a 19-year-old college student, continued their assault against the verdict on Tuesday, filing papers that — again — claim prosecutors withheld important evidence and misled jurors at his trial.

Mr. Giuca, now 32, was convicted in 2005 of taking part in the fatal shooting of Mark S. Fisher, a Fairfield University sophomore who died on Oct. 12, 2003, after a night of drinking on the Upper East Side.

Back from college for the weekend and without enough cab fare to get home to the suburbs in New Jersey, Mr. Fisher found himself, as night turned into morning, at Mr. Giuca’s house in Prospect Park South, with a group of people he did not know. As the sun came up, the police found Mr. Fisher’s body, wrapped in a blanket, a few blocks from the house.

At the closely watched trial, prosecutors from the Brooklyn district attorney’s office argued that Mr. Giuca and a friend, Antonio Russo, were members of a fledgling gang called the Ghetto Mafia who went after Mr. Fisher to gain street credibility. They said that Mr. Giuca was jealous over a woman Mr. Fisher had been flirting with and was angry at him for drunkenly sitting on his parents’ table. Separate juries found Mr. Giuca and Mr. Russo guilty, and both were sentenced to 25 years to life in prison.