By Scott Malone

FALL RIVER, Mass. (Reuters) - The judge in former New England Patriots star Aaron Hernandez's murder trial on Thursday barred a local television cameraman from the trial after he drove a truck that followed a bus full of jurors, saying the incident could have led to a mistrial.

The jury deliberated for a third day without reaching a verdict on whether Hernandez, 25, is guilty of murdering an associate, in the first of two murder trials he faces this year.

After the jury in Fall River, Massachusetts, determines whether he killed semiprofessional football player Odin Lloyd, Hernandez will face a trial in Boston on charges of fatally shooting two Cape Verdean men outside a nightclub in 2012.

Bristol County Superior Court Judge Susan Garsh said two of the 15 jurors reported they had been followed by a truck from WHDH television, an NBC affiliate, and summoned the cameraman who had driven the truck, Robert Cusanelli, to court.

The cameraman said he had made no effort to interact with any of the jurors.

"I know that's forbidden," said Cusanelli.

Garsh said she would ban him from covering the rest of the trial but held off on an earlier threat to eject the station.

"I am not going to further sanction WHDH as an entity," Garsh said, after warning that it was legally required that no juror be approached, and if one was, it could lead to a mistrial.

Of the 18 people, 12 jurors and six alternates, originally seated in the case, three have already been excused from service.

The former New England Patriots tight end has pleaded not guilty. His lawyers argued in closing statements on Tuesday that he had witnessed the shooting in North Attleborough, Massachusetts, but did not commit it.

Prosecutors contend that Hernandez and two friends, in the early hours of June 17, 2013, picked Lloyd up at his home in Boston and drove him to the industrial park where his body was found riddled with bullets later that day.

If convicted of first-degree murder, Hernandez would be sentenced to life in prison without the possibility of parole.

Hernandez had been a rising star in the National Football League with a $41 million contract when he was arrested on June 26, 2013.

(Editing by Bernadette Baum, Ted Botha, Andrew Hay and Jonathan Oatis)