Former NFL star Aaron Hernandez has been convicted of first-degree murder in the execution-style slaying of a Boston man two years ago — and a year after Hernandez signed a $40 million contact with the New England Patriots.

He was sentenced to mandatory life in prison without parole.  Hernandez is 25 years old.

The Bristol County jury of seven women and five men returned the verdict Wednesday morning, capping a 10-week trial during which prosecutors built their case on circumstantial evidence, lacking eyewitnesses or the murder weapon.

Stoic throughout the trial, Hernandez shook his head slightly and appeared to mouth “you’re wrong” when the judge announced the verdict. His mother and fiancée, with whom he has a two-year-old daughter, broke out in tears. He told them to “stay strong, stay strong” as he was led from the courtroom in handcuffs.

It took the jury seven days to reach a verdict. The trial lasted 10 weeks and included 132 prosecution witnesses (including Patriots owner Robert Kraft), 437 exhibits but only three defense witnesses. Hernandez was also found guilty of unlawful firearm and ammunition possession charges.

Critical to the verdict was a concession by Hernandez’ lawyers on the trial’s final day that he was present when Odin Lloyd, 27, a landscaper and semipro football player, was killed June 17, 2013, in a secluded industrial park a mile from Hernandez’ spacious suburban home seven miles from Gillette Stadium, where he played tight end for the Patriots.

“We were all shocked by that,” said one juror who asked that her name not be used.

His lawyers insisted he was not the trigger man, blaming instead two companions who were with Hernandez and Lloyd that fateful night. The companions – Ernest Wallace and Carlos Ortiz – did not testify against Hernandez. They have also been charged with Lloyd’s murder and will be tried separately.

Defense attorney James Sultan depicted Hernandez as “a 23-year-old kid”  who witnessed a “shocking killing committed by someone he knew. He didn’t know what to do, so he put one foot in front of the other. He’s not charged with being an accessory after the fact.”

Prosecutors portrayed Hernandez as a paranoid, easy-to-anger person who killed Lloyd because he was upset at him for a reason that was never fully explained in court. They called several witnesses who testified to his hot temper, including one former friend who said he was shot in the face by Hernandez.

But the prosecution case was mainly built on surveillance video tapes of the entrance road leading to the murder scene and footage from Hernandez’ home security system that showed him holding what looked like a gun only minutes after Lloyd’s slaying. They also said they found his DNA a the murder scene.

The entrance video showed four persons in a car rented by Hernandez entering the industrial park where a jogger found Lloyd’s body the next day, and only three people in the car when it departed the park. An expert witness testified that Hernandez appeared to be holding a .45 Glock handgun in his home security video, the same weapon used to kill Lloyd.

Shayanna Jenkins, Hernandez’ fiancée, testified that Hernandez instructed her to get rid of a box from the couple’s home, and she disposed of it in a dumpster, though she couldn’t remember where. She also said she did not know what was in the box.

Prosecutors said they believed the box contain the murder weapon. A search of landfills in the area failed to find the box.

Jenkins was granted immunity to testify for the prosecution, but she remains charged with perjury before the grand jury that indicted Hernandez. Jenkins’ sister Shaneah was Lloyd’s girlfriend at the time of his death. The arrest of Hernandez led to the sisters’ estrangement.

Prosecutors said Hernandez and Lloyd were at a Boston nightclub together two nights before the murder, and Hernandez appeared to get angry and abruptly leave the club when Lloyd started talking with two women, possibly about Hernandez’ personal life.

That set in motion, they said, his plan to kill Lloyd, with the assistance of Wallace and Ortiz.

Completion of the Lloyd trial clears the way for prosecution of a completely separate double-murder charge against Hernandez. He is accused of the 2012 drive-by shooting of two young men in downtown Boston, murders that were unsolved until investigators looking into the Lloyd murder also connected Hernandez to the slayings of Daniel Abreu and Safiro Futado. Authorities claim Hernandez was angry because Abreu bumped into the Patriots player at a nightclub, causing him to spill his drink.

Hernandez played three years for the New England Patriots. He signed a five-year $40 million extension in 2012 just prior to the Boston drive-by murders.

The team terminated him immediately upon learning of his arrest for the Lloyd murder, and declined to pay a multimillion bonus he was due. Had Hernandez been found innocent, the Patriots could have been required to pay it.