The attorney representing Jabrai Jordan Copney—the alleged gunman in the May 2009 Kirkland House shooting—has filed a series of motions that seek to exclude discussion of an alleged prior crime and evidence that the defense says was inappropriately seized by police.

Prosecutors say that Copney and Blayn Jiggetts—an alleged accomplice in the Kirkland killing—stole drugs at gunpoint from two Yale students in New York City in 2008.

Copney’s attorney, John A. Amabile, said he hopes to bar discussion of the alleged New York crime during Copney’s upcoming trial, in which he will be tried for the murder at Harvard of 21-year-old Cambridge resident Justin Cosby.

The defense has filed a motion to dismiss all charges related to the New York robbery, based on the grounds that a Massachusetts court does not have jurisdiction over a crime that occurred in another state, according to Amabile.

The armed robbery in New York served as a blueprint for the drug rip-off, which went tragically wrong, in Kirkland’s J-entryway on May 18, 2009, according to testimony in court documents by individuals with knowledge of both incidents.

Whether or not the New York-related charges are dropped, Amabile is seeking to forbid the robbery from being mentioned as evidence during Copney’s murder trial.

Amabile said that allowing the evidence to be included would prejudice the jury toward seeing Copney as a “bad person.”

The Massachusetts Guide to Evidence states that “evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person.” But such evidence can “be admissible for other purposes, such as proof of motive, ..., intent, preparation, [or] plan.”

Under these guidelines, the prosecution may seek to discuss the New York crime in order to establish that the defendant’s intent upon entering Kirkland’s J-entryway was to steal—rather than buy—drugs from Cosby.

Currently, the prosecution seeks to include charges for both the New York robbery and the shooting in Kirkland House in a single trial. The defense seeks to either dismiss the charges altogether, or—if the motion to dismiss fails—to consider the two incidents in separate trials.

The motion filed by the defense contends that the robbery in New York was a “totally different and unrelated act, transaction, or event” from the Kirkland shooting.

According to Amabile, a judge is also considering whether a jacket found by police in a container in Brittany J. Smith’s closet, which the prosecution contends Copney was wearing at the time of the shooting, is admissible as evidence in the case.

Copney alleged in a motion filed in February that the seized property—which Amabile told The Crimson was the “distinctive jacket” mentioned by witnesses—was not in plain view when police entered the room.

According to court documents, forensic investigators have found gun-shot residue on the jacket.

The defendant’s motion claims that the seizure was “conducted without probable cause, without consent, and without a valid search warrant.”

The search was conducted in Smith’s Lowell House dorm room. Smith, who was a Harvard senior and Copney’s girlfriend at the time of the shooting, has been charged with serving as an accessory after the fact to the murder, among other counts.

Rulings on the admissibility of the jacket and the treatment of the New York crime are likely to be handed down early next week, according to Amabile.

Copney’s trial is scheduled to begin on April 4.

—Xi Yu contributed reporting to this story.

—Staff writer Hana N. Rouse can be reached at hrouse@college.harvard.edu.

—Staff writer Julie M. Zauzmer can be reached at jzauzmer@college.harvard.edu.