WOBURN, Mass.—As the second week of the trial of alleged Kirkland shooter Jabrai Jordan Copney came to a close, an alleged cooperator in the crime was grilled on the witness stand by the defense.

Prosecutors have granted the witness, Blayn Jiggetts, a plea bargain in exchange for testifying. On the stand Friday, Jiggetts said that Copney planned to rob Justin Cosby, the victim, and fired the shot that killed him—but defense attorney John A. Amabile has said since the opening statements that Jiggetts was actually the man who pulled the trigger.

In court on Friday, Amabile spent nearly three hours dissecting Jiggetts’ version of the events in the case.

Amabile suggested that Jiggetts and Jason Aquino—the third man who was indicted for the murder and who has also reached a plea agreement—collaborated on a story which would pin Copney for the murder.

Amabile established in his questioning that Jiggetts and Jason Aquino were friends since childhood, whereas Copney had met them both within the year that the shooting took place.

After noting that Jiggetts has called Aquino “cousin” because of their close camaraderie, Amabile referred to Aquino as “cousin Jason” repeatedly during his cross-examination.

“We don’t know what happened; it’s all Jabrai Copney—that’s the story you and your pal, your cousin Jason Aquino talked about,” Amabile said. “You made an agreement that the two of you, who didn’t care what happened to Copney, would lie to the police.”

Jiggetts denied Amabile’s interpretation, saying that Copney himself concocted a cover story that the men originally told to investigators.

Jiggetts said on the stand that he sought out the gun, which was owned by Aquino, and brought it from New York City, the three men’s hometown. Jiggetts further admitted to loading the gun in a Harvard dorm room before the shooting. He said he pulled the gun in the Kirkland annex basement to threaten Cosby—the eventual shooting victim—before handing it over to Copney.

“Why did you bring bullets with you?” Amabile asked.

“I was told by Jabrai it was vital because we were dealing with a street kid,” Jiggetts said, referring to Cosby, the intended target of an armed robbery of marijuana which Jiggetts says the three men had planned.

Amabile continued, “You brought bullets because you wanted to be prepared to shoot somebody. Is that correct, sir?”

When Jiggetts replied, “Not at all,” Amabile came close to shouting.

“That’s the only reason you need bullets,” he said. “Is that correct?”

In the final line of questioning in his lengthy cross-examination, Amabile focused on the fact that in exchange for his cooperation against Copney, Jiggetts has been promised a 9 to 12 year prison sentence, two years of which he has already served—as opposed to the life sentence without parole which Copney could face for a first-degree murder conviction.