Ex-NFL star Aaron Hernandez, who is already serving a life sentence for a 2013 murder, was acquitted on Friday in a 2012 double killing that prosecutors said was fueled by his anger over a spilled drink.

The former tight end for the New England Patriots wept quietly as the verdicts were read in Boston. A few moments later, he looked back at his fiancee and nodded somberly as relatives of the victims sobbed loudly. A defense attorney hugged him.

After six days of deliberations, the jury found Hernandez not guilty of first-degree murder in the killings of Daniel de Abreu and Safiro Furtado. It convicted him of a single charge: unlawful possession of a gun. The judge sentenced him to an additional four to five years in prison, separate from his existing life sentence.

Prosecutors said Hernandez opened fire on their car because he felt disrespected when one of the men bumped into him and spilled his drink at a Boston nightclub. The defense team pointed the finger at Alexander Bradley, a close friend of Hernandez who was with him the night of the shootings.

Hernandez was also acquitted Friday of shooting Bradley in the face months later to try to silence him as a witness. Bradley lost his right eye.

Hernandez, 27, is already serving a life sentence for the 2013 killing of Odin Lloyd, a semi-professional football player who was dating the sister of Hernandez’s fiancee. Prosecutors in the double-murder trial weren’t allowed to mention his conviction in Lloyd’s case.

Bradley claimed Hernandez became enraged after de Abreu bumped into him while dancing. He said Hernandez later opened fire on the men’s car as they waited at a stoplight.

Hernandez’s lawyers said it was Bradley who shot the men over a drug deal. The defense hammered at Bradley’s credibility, citing his immunity deal with prosecutors to testify against Hernandez, his role as the driver of the car the night of the shootings and his criminal record. Bradley is serving a five-year prison term in Connecticut for firing shots at a Hartford nightclub in 2014.

Prosecutors introduced evidence at trial that Hernandez got a tattoo that memorialized the double saying. California tattoo artist David Nelson testified that Hernandez requested an image of a revolver with the gun barrel facing forward.

Hernandez wanted five bullets visible in the cylinder of the gun and one cylinder empty, Nelson said. Authorities said Hernandez fired five shots from a revolver into the car carrying de Abreu and Furtado.

Hernandez grew up in Bristol, Connecticut, and played for the Patriots from 2010 to 2012. About six weeks after Furtado and de Abreu were killed, Hernandez signed a five-year, $40m contract with the Patriots and went on to play another season before Lloyd was killed. He was cut from the team shortly after he was arrested in Lloyd’s killed in June 2013. He was not charged in the 2012 killings until 2014.

In his first trial, jurors deliberated for 36 hours over seven days before convicting him of murder. Jurors in the trial that concluded Friday deliberated for about 37 hours.