FALL RIVER, Mass. — Prosecutors laid out what they called compelling forensic evidence — Aaron Hernandez’s DNA on a marijuana cigarette shared with the friend they say he killed — as the ex-NFL star’s trial got underway.

Jurors were to hear more testimony Friday in the case against the former New England Patriots standout, whose lawyers portrayed him as a man with “the world at his feet” and no reason to kill.

With his ex-teammates about to play in the Super Bowl, Hernandez listened intently to Thursday’s opening statements. They offered insights into the prosecution’s case against him and the defense’s strategy to prove his innocence in the 2013 slaying of semipro football player Odin Lloyd.

Hernandez, 25, is charged in the shooting death of 27-year-old Lloyd, who was dating the sister of Hernandez’s fiancée.

Lloyd’s bullet-riddled body was found in an industrial park near Hernandez’s North Attleborough home, not far from Gillette Stadium.

Hernandez — who had a $40 million contract as a tight end but was cut by the Patriots hours after his 2013 arrest — could get life in prison if convicted. On Sunday, the Patriots meet the Seattle Seahawks in the Super Bowl.

In a separate murder case that has yet to come to trial, Hernandez was charged last year in Boston with killing two men in 2012 after someone spilled a drink on him at a nightclub.

District Attorney Patrick Bomberg showed the jury before-and-after security video to connect Hernandez to Lloyd’s killing.

He played footage that he said showed Lloyd getting into a Nissan Altima rental car driven by Hernandez, then video from the NFL player’s home, taken shortly after Lloyd was killed, without Lloyd in the car.