Aaron Hernandez, who was charged with murder Wednesday, is also being investigated as the possible gunman in a double homicide in Boston in 2012, according to a law enforcement official. A second law enforcement official confirmed that Hernandez, the former NFL tight end, has been connected to the homicides, which occurred after a fight in a Boston nightclub.

The twin killing at a city intersection early one morning last July has remained unsolved. Police knew that Hernandez had been in the nightclub called Cure that night but considered his presence of no significance.

“They knew he was in there,” the official, who spoke on condition of anonymity because the investigation is continuing, said of the club. “But it was thought that he was just a sports star at the bar.”

When Hernandez was linked last week to the killing of 27-year-old Odin Lloyd, Boston police decided to take another look at his possible role in last year’s killings.

    Most Read Stories

Further investigation led police to tie Hernandez to that killing, said the official. The official said that Hernandez is believed to have fired the shots that killed the two men, Daniel Abreu, 29, and Safiro Furtado, 28.

The fight inside the club took place between Abreu and Furtado and a group of men that police have been told included Hernandez.

Abreu and Furtado left the club with three other men in a BMW sedan. Abreu, who was driving, came to a stop at a traffic light when an SUV with Rhode Island license plates pulled alongside. The BMW was then sprayed with gunfire, which killed Abreu and Furtado. The three other men in the car survived. No suspects were identified, but Boston police never closed the investigation.

The next month, the New England Patriots gave Hernandez a $40 million contract extension. He had five touchdowns in 10 games last season.

On Wednesday, Hernandez, 23, was charged with murder and five gun-related offenses in Massachusetts in connection with the June 17 murder of Lloyd, whose body was found in a secluded section of an industrial park that is less than a mile from Hernandez’s home in North Attleborough, Mass.

Hernandez pleaded not guilty and was held without bail. On the murder charge, he faces a life sentence without parole.

Wednesday night in Connecticut, a second man was arrested in connection with the Lloyd murder — Carlos Ortiz, 27, from Bristol, Conn. He was charged with carrying a firearm without a license.