As a judge heard arguments for the first time relating to B. Denise Cosby’s wrongful death lawsuit against Harvard for the 2009 murder of her son in Kirkland House, lawyers for Harvard said that the University cannot be held responsible for the drug deal gone wrong, and the suit should be dismissed.

Harvard’s attorneys maintained that the University had no duty to protect 21-year-old Justin D. C. D. Cosby, who came to the Harvard dormitory for what he believed was a marijuana deal. Instead, he was held at gunpoint by three men demanding that he hand over the drugs. When he refused, one of the men shot him.

In oral argument in Middlesex Superior Court on Wednesday, Harvard’s lead attorney Martin F. Murphy stressed the point that has been the University’s main contention since the suit was filed in May. “Particularly [when] the plaintiff himself has come onto the property in order to engage in dangerous activities,” Murphy argued, “the law makes it clear that [Harvard] doesn’t have that duty of safety to [Cosby].”

Neither side has contested that Cosby came to Harvard that day to sell drugs. But Denise Cosby’s lawyers argued Wednesday, as they have since May, that the dangerous situation developed only because of Harvard’s lax enforcement of its own regulations. One of the three men involved in the hold-up, Jabrai Jordan Copney, had been living for months with his girlfriend, Harvard senior Brittany J. Smith, in her Lowell House single—a clear violation of rules printed in Harvard's student handbook and elsewhere.

As a result of Harvard’s inattention, Cosby’s lawyers say, Copney ran “a criminal enterprise” out of Smith’s Lowell dorm room. Before Cosby’s murder in May 2009, Copney and his friend Blayn Jiggetts, also later involved in Cosby’s killing, had used a firearm to steal drugs from two Yale dealers whom Cosby met during Harvard-Yale weekend.

“[Copney] was there for two semesters,” Cosby’s lead attorney Isaac H. Peres said, “not two days, not three days.... The only reason this became a situation is because of [Harvard’s] negligence.”

Copney was convicted of first-degree murder in Middlesex Superior Court last year and is serving a life sentence without the possibility of parole. His two associates, Jiggetts and Jason F. Aquino, each pleaded guilty to manslaughter, and Smith pleaded guilty to accessory charges.

Denise Cosby and Gregory Daniel Cosby, the uncle of the shooting victim, watched the proceedings.

“We’re cautiously optimistic. You never know about these things, but we felt that it went well and that [the judge] understood our argument,” Peres said afterward. The judge will hand down an opinion on whether the case should be dismissed at an unannounced time.

—Staff writer Matthew Q. Clarida can be reached at clarida@college.harvard.edu.