WOBURN, Mass.—The closing arguments in the Kirkland murder trial yesterday were characterized by sharply different versions of the same story as the defense blamed the shooting on another man, calling him a “homicidal maniac,” and the state responded by likening that claim to “fantasy.”

During statements in court yesterday, the state contended that Jabrai Jordan Copney should be found guilty of first-degree murder for planning and executing an armed robbery that ended in a killing in the basement of a Harvard dormitory. Meanwhile, the defense continued its strategy of deflecting blame away from the defendant, arguing that the encounter was not a robbery and that another man fired the fatal shot.

In his closing argument, Assistant District Attorney Daniel J. Bennett ’85 outlined the state’s allegations about the events surrounding the fatal shooting of 21-year-old Cambridge resident Justin Cosby in May 2009.

Bennett said that Copney had expressed a belief that drug dealers make good targets for robberies because they will not report the theft of their wares to police.

According to the series of events presented by the prosecution, Copney collaborated with Jason Aquino and Blayn Jiggets to rob Cosby of a large quantity of marijuana. By posing as a Harvard student looking to buy drugs for a party, Bennett said that Copney lured Cosby into an art room in the basement of Kirkland’s J-entryway.

There, the prosecutor said, Copney fired three shots with the intent of killing Cosby when he refused to hand over the marijuana that Cosby thought he had come to sell.

Jiggets and Aquino were both charged with first-degree murder but have pleaded guilty to the lesser charge of manslaughter.

“Jabrai Copney made a decision,”

Bennett said. “His decision was that Justin Cosby’s life was not worth as much as that marijuana. He made that decision when he planned to rob him, something that was inherently dangerous. He made that decision when he shot him—the result of that decision was that Justin Cosby bled to death on the corner of Dunster Street.”

In one phase of his argument, Bennett sought to prove that Copney intended to rob the victim by asking over a dozen questions, each one beginning with “If it’s a drug purchase rather than a robbery...”

“Why do they have a gun with them?” Bennett asked. “Why do they pick a place where there’s only one way in and one way out, like that art room?”

Defense attorney John A. Amabile, who chose to call no witnesses during the trial, spoke for more than twice as long as Bennett during his closing argument. He urged the jury to accept a very different story—at times gesticulating with the alleged murder weapon and shouting “Boom! Boom!” and “Bang! Bang! Bang!” to dramatically reenact his version of events.

Amabile drew on the testimony of one of the prosecution’s witnesses—ballistics expert Stephen Walsh, who examined the scene of the crime on the day of the shooting and the following day—as a basis for his theory that Jiggetts was the shooter rather than Copney.

Interpreting evidence that Walsh presented about the three bullets that were fired—one into the wall of the entryway stairwell, one into the entryway’s wooden door, and one into Cosby’s abdomen—Amabile said that the shooter was standing on the staircase rather than at its base, where Jiggetts testified Copney stood to fire at Cosby.

“The physical evidence tells the story in this case, ladies and gentlemen, not the garbage testimony of Blayn Seven-Years-for-Killing-Somebody-and-I’m-Walking-Free Jiggetts,” Amabile said, repeatedly referring to the fact that Jiggetts has been promised a 9 to 12 year sentence, two years of which he has already served, in exchange for testifying against Copney.