Updated

One of the inmates suspected in the stabbing of an Ohio prison guard is a three-time convicted killer.

Joe Hale, an assistant prosecutor in Scioto County, says suspect Casey Pigge (pij) was removed from the Southern Ohio Correctional Facility after Tuesday's attack and transferred to a state prison in Youngstown.

Pigge had previously been convicted of killing two fellow inmates in separate cases and a woman.

The Ohio State Highway Patrol says two inmates on Tuesday attacked the guard in the prison infirmary with metal weapons.

Prisons spokeswoman JoEllen Smith on Wednesday confirmed a "serious inmate on staff assault." Smith says corrections officer Matthew Mathias remains hospitalized in stable condition and the prison remains on lockdown.

It's unclear if Pigge has an attorney.