A grand jury indicted Aaron Hernandez Thursday on charges of assault and battery, and threats to do bodily harm.  An arraignment date for the new indictment, which is unrelated to the Odin Lloyd case, hasn't yet been announced.

The Bristol County District Attorney's Office announced the indictment Thursday in a press release:

"A Bristol County Grand Jury this afternoon indicted Aaron Hernandez on charges stemming from an alleged assault, which occurred inside the Bristol County House of Corrections in Dartmouth on February 25, 2014, and an alleged threat made inside the same facility on November 1, 2013."

TMZ reported in February Hernandez was involved in a jailhouse brawl with a fellow inmate, who was restrained at the time.  Bristol County Sheriff Thomas Hodgson announced on March 6 the department had filed a criminal complaint against Hernandez in connection to the alleged assault.

"The investigation would indicate that our officers believed that it absolutely needed to go to a criminal complaint," Hodgson said on Thursday, via WHDH.  "... I can just tell you that there was, you know, an altercation that took place between Mr. Hernandez and another inmate.  I can't get into really the details now that it's gone to this level of complaint."

The inmate had previously harassed Hernandez, according to TMZ.

Although the District Attorney's Office didn't elaborate on the specifics of the threat mentioned in Thursday's indictment, it likely stems from a reported incident between Hernandez and a correctional officer.

TMZ reported in April that investigators questioned a former inmate who was locked up near Hernandez about a threat the ex-NFL star allegedly made to a correctional officer in 2013. 

"Investigators asked if Hernandez had threatened to kill the guard -- who blew the whistle on Aaron when he was trying to deviously score extra food inside the joint," TMZ published on April 15.

The former inmate denied Hernandez threatened the correction officer.

Hernandez is being held without bail while awaiting trial for the first-degree murder of Lloyd.  Hernandez is also under investigation for his possible involvement in a 2012 unsolved double homicide in Boston, as well as his possible involvement in an interstate gun trafficking ring. 

He also faces two lawsuits: a wrongful death lawsuit filed by the mother of Lloyd and a lawsuit from an associate, Alexander Bradley, who alleges he was shot in the face by Hernandez.