LEXINGTON, Okla. — Robert Bever is serving a life sentence in a prison in Lexington, Oklahoma, for the stabbing death of his five family members.

The Department of Corrections says the 22-year-old inmate tried to attack prison staff with an 8-inch long "sharpened instrument" on Monday.

A DOC report says Bever approached two staff members from behind in a dayroom at the Joseph Harp Correctional Center.

One of the workers grabbed him and he complied with orders to drop the weapon and drop to the ground.

DOC spokesman Matt Elliott said Wednesday that no one was seriously hurt and charges are unlikely.

Bever pleaded guilty in 2016 to stabbing his parents and siblings to death and attacking another sibling in their Broken Arrow home.

His brother, Michael Bever, was convicted in 2018 in the same attack.