An inmate accused of attacking correction officers inside a Massachusetts prison last month is scheduled to be arraigned on Thursday.
Thirty-six-year-old Heriberto Rivera-Negron is one of three inmates accused in the attack at the Souza-Baranowski Correctional Center in Lancaster last month. He is charged with mayhem, armed assault to murder and assault to murder.
One of the correction officers was stabbed up to 12 times in the maximum security prison. Four other correction officers were also hurt.
The other two inmates accused in the attack will be arraigned at a later date.
