By Scott Malone

BOSTON (Reuters) - Convicted murderer and former National Football League star Aaron Hernandez pleaded not guilty on Thursday to charges he intimidated a witness in a double-murder case against him by shooting the man in the face.

Hernandez, 25, is accused of shooting former friend, Alexander Bradley, in February 2013 after he referred to the 2012 murders in Boston.

Hernandez is awaiting trial on the double-murder charge, with a judge urging the trial begin in late November or early December.

Hernandez was sentenced last month to life in prison for the June 2013 murder of an acquaintance, Odin Lloyd, whose body was found in a North Attleborough, Massachusetts, industrial park not far from the former New England Patriots tight end's home.

Bradley had been with Hernandez the night that he shot dead Cape Verde nationals Daniel Abreu and Safiro Furtado outside a Boston nightclub, from the moment Hernandez became angry when one of them spilled a drink through when Hernandez followed them in a car and opened fire, said Patrick Haggan, assistant district attorney.

"The defendant fully knew that Alexander Bradley was the only eyewitness who could identify him as the perpetrator of that crime," Haggan said. "Mr. Hernandez became increasingly paranoid and fearful, convinced that law enforcement was watching him."

Hernandez shot Bradley while the two were on a trip to Florida, where Hernandez grew concerned police were following him and became angry when Bradley referred to "stupid stuff" Hernandez had done in Boston, Haggan said.

A new tattoo reading "Lifetime" and appearing to feature a star could be seen on the right side of his neck, above his shirt collar, as he sat in court.

Bradley, who lost an eye in the shooting, testified during Hernandez's trial in Fall River, Massachusetts, over the killing of Lloyd. At that time he was not allowed to testify about the shooting incident.

Hernandez had been a rising star in the NFL with a $41 million contract when he was arrested in June 2013 and charged with Lloyd's murder. The Patriots cut him from the team within hours.

Additional charges on the 2012 double murder followed in May 2014.

Media reports this week quoted a law enforcement source as saying Hernandez faced disciplinary action for allegedly serving as a lookout during a fight at a Massachusetts prison.

(Reporting by Scott Malone; Editing by Peter Cooney and Lisa Shumaker)