Aaron Hernandez had a court appearance last December. (Matt Stone / AP)

Aaron Hernandez has been indicted by a grand jury on two counts of first-degree murder in connection with a July 2012 double murder in Boston.

Hernandez, the former New England Patriots tight end, has been in jail in Massachusetts since late last June as he awaits trial for the shooting death of Odin Lloyd. That shooting is believed to have been linked to the drive-by shooting deaths of Safiro Furtado and Daniel Abreu after an alleged nightclub incident in Boston’s South End in the summer of 2012. The men were shot by someone who pulled up beside their car and opened fire and Hernandez was seen on surveillance footage in the same nightclub as the victims the night of the attack, authorities have said.

In a mid-morning press conference, Suffolk District Attorney Daniel F. Conley alleged that after a “chance encounter” at a Boston club, Hernandez trailed the men in his car, then pulled along side theirs and fired a pistol “multiple times” into the car, killing Abreu and Furtado and wounding another man.

“For us, this case was not about Aaron Hernandez. This case was about two victims, who were stalked, ambushed, and senselessly murdered on the streets of the city they called home,” Conley said.

Hernandez is expected to be arraigned next week. “This was a chance encounter where two young men were out … and basically had an encounter that led to their deaths,” Police Commissioner William Evans said. “I remember going to the scene that morning. … It was a terrible tragedy.”

The indictment raises the unsettling possibility that he signed a $40 million contract extension six weeks after his alleged involvement in the double shooting and played an entire NFL season afterward. Hernandez has pleaded not guilty to the June 2013 murder of Lloyd, who was dating the sister of his fiancee, Shayanna Jenkins. His body was found not far from Hernandez’s North Attleboro, Mass., home. No trial date has been set and Hernandez is being held without bail in the Bristol County jail.

Immediately after signing that contract extension in August 2012, Hernandez told reporters: “This is probably one of the best days of my life. I’ll remember this day forever. I just hope I keep going, doing the right things, making the right decisions so I can have a good life, and be there to live a good life with my family.”