The Bristol County district attorney's office said Hernandez was indicted Thursday on charges of assault and battery and threats to do bodily harm. The statement said the alleged assault occurred Feb. 25 at the Bristol County House of Correction in Dartmouth, and the alleged threat occurred there on Nov. 1.
The February scuffle allegedly occurred when an inmate was being transported from the jail's infirmary. The man, identified as Andrew Booker, and Hernandez allegedly exchanged words. Hernandez allegedly punched Booker and knocked him to the ground. Neither was injured.
Booker's attorney, Michael P. Malone, has told reporters his client will not testify against Hernandez.
"He doesn't want to be a rat," Malone said.
The threats made on Nov. 1 reportedly involve Hernandez allegedly threatening to shoot and kill a guard at the Bristol County jail after the guard blew the whistle on his schemes to try to get extra food from his jailers.
An arraignment date hasn't been set.
Hernandez is being held at the jail without bail after pleading not guilty to murder in the 2013 death of 27-year-old Odin Lloyd, a Boston man who was dating the sister of Hernandez's fiancée.
Information from The Associated Press was used in this report.