A Sacramento County jury has convicted a prison inmate of repeatedly stabbing a prison guard.

Prosecutors said Friday that Erik St. John may face life in prison when he is sentenced next month for assault, resisting, and four counts of possessing inmate-made weapons.

He refused to leave his California State Prison-Sacramento cell in 2015, hiding behind a sheet tied to an overhead light fixture. When correctional officers entered his cell, he leaped from behind the sheet and stabbed one officer behind his protective shield before he was subdued.

Officials did not say how badly the officer was injured.

St. John was also found with weapons three other times.

He has prior convictions for arson and making criminal threats with a hate crime allegation.