Middlesex District Attorney Gerry Leone speaks during a visit to Cambridge last year. Leone announced a guilty plea today in the 2009 shooting of a Cambridge resident in a Harvard dorm. (Photo: Marc Levy)

A New York man pleaded guilty today in connection with the shooting death of Justin Cosby, 21, of Cambridge, Middlesex District Attorney Gerry Leone said.

Jason Aquino, of Manhattan, pleaded guilty in Middlesex Superior Court to charges of manslaughter, armed robbery and willfully misleading a grand jury.  Judge Howard Whitehead will sentence the defendant May 2.

“Today, Jason Aquino is held accountable for his part in the killing of Justin Cosby by admitting the role he played and his culpability in the shooting death of this young man, which occurred in broad daylight on the campus of one of the world’s premier educational institutions,” Leone said.  “With this defendant’s admission, we now move forward with our prosecution against the man we alleged shot the victim and the remaining co-conspirators.”

An investigation determined that Aquino and his fellow suspects and New Yorkers, Jabrai Jordan Copney and Blayn Jiggetts, set up a meeting with Cosby to rob him during a drug deal. Although a Cambridge resident and Cambridge Rindge & Latin high school graduate, Cosby also was not a student at Harvard; he has been called a drug dealer to students there.

During the May 18, 2009, meeting in a common area inside Harvard’s Kirkland House, shots were fired, one of which hit Cosby.

Harvard University Police and Cambridge Police went to Kirkland House, on Dunster Street in Cambridge, at 4:48 p.m. on reports of shots fired. But Cosby, suffering from a gunshot wound to the abdomen, had left Kirkland House and run to the intersection of Dunster and Mount Auburn streets, where he collapsed. He was taken to Beth Israel Hospital and pronounced dead at about 4 a.m.

Copney, who has been called the leader of the plan and is accused of firing the fatal shot, has pleaded not guilty and is set for trial April 4 on first-degree murder charges.

Jiggetts, who has pleaded guilty to manslaughter, will testify against Copney, The Boston Globe reports.

As to the Harvard students involved, the Globe says:

The New York men gained access to the secure dormitory from Brittany Smith, Copney’s girlfriend and a Harvard senior just one week from graduation. Smith also allegedly stashed the murder weapon in a friend’s room at another Harvard dorm. Smith’s long-time friend who was also Harvard senior, Chanequa Campbell, has testified she knew the men were coming to the campus, and that she knew Jiggetts would be armed with a handgun.

Campbell, a cooperating witness, has not been charged. Smith has pleaded not guilty to three counts of accessory after the fact, illegal possession of a firearm, and two counts of witness intimidation.

Smith is alleged to have given her Harvard issued ID, which works as an electronic key card, to the defendants to allow them to enter the building where the fatal shooting occurred, said Leone’s deputy director of communications, Cara O’Brien. After the shooting, Smith allegedly hid the murder weapon under a friend’s dormitory bed.

Aquino, Copney, Jiggetts and Smith fled to New York City that evening on a bus from Boston. Smith came back with Copney the next day, O’Brien said, and when questioned by Harvard Police about her ID card, lied to them, telling them she’d the pass key in her possession the entire time.