Police said Thursday that 25-year-old Ruben Porter also is charged with assault in a detention facility and possession of a deadly weapon during the commission of a felony.
Porter, who is serving time for attempted robbery, assault and other crimes, is accused of stabbing a 22-year-old prison guard twice with a homemade shank Tuesday night in a maximum security unit at the prison in Smyrna, prompting a prison lockdown.
Porter also is accused assaulting a 53-year-old guard who was treated for a facial injury.
The guard who was stabbed was reported in good condition following surgery at Christiana Hospital in Newark.