More trouble for former NFL star Aaron Hernandez.  The Bristol County Sheriff's Office filed a criminal complaint against Hernandez for allegedly attacking another inmate, FOX 25 and WHDH report. 

The complaint, which Bristol County Sheriff Thomas Hodgson announced on Thursday, could result in Hernandez being charged with assault and battery.  A magistrate will review the complaint and determine whether sufficient probable cause exists to charge Hernandez. 

If probable cause does exist, Hernandez could have a hearing before his arraignment.

The fight between Hernandez and the inmate reportedly occurred in late February.  TMZ first reported the alleged jailhouse altercation and claimed, according to their sources, the inmate had previously harassed Hernandez.  The report also indicated the inmate was shackled when Hernandez, unrestrained, attacked him.

Hodgson confirmed a brief fight involving Hernandez did occur but didn't result in any injuries.  He declined to elaborate.

"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 has not been charged.

It's unclear how Hernandez and the inmate, both of whom were supposed to be in isolation, came into contact with each other.  Hodgson said the guards followed procedure and are not facing disciplinary action.

"Our officers followed the proper procedures, however, we did identify the fact that we had gone to extra lengths to make sure, as we would for a sex offender or anyone else who is a high-profile person, to do everything we could to restrict anyone in the same unit from hurting that individual," Hodgson said, via Fox 25.  "What we didn't anticipate in the case of Mr. Hernandez is that the role would have been reversed."

Hernandez, 24, is currently being held without bail while awaiting trial for the first-degree murder of Odin Lloyd.  He pleaded not guilty, and his attorneys have called the Commonwealth's case against him "weak" and "circumstantial."

He is also a suspect in a 2012 unsolved double homicide in Boston.  In addition, he faces three civil suits: two from the double homicide and one from a former acquaintance who alleges Hernandez shot him in the eye.