(ONN) – The family of a correctional officer killed on Christmas Day last year while on duty is suing the Ohio Department of Rehabilitation and Correction.

The department said inmate Rashawn Cannon beat Officer Andrew Lansing to death last year inside a guard shack in the prison yard of the Ross Correctional Institution.

A lawsuit filed by Lansing’s estate claims the attack was “foreseeable” and “preventable” and alleges Cannon threatened to kill Lansing months before his death.

We reached out to the department who tell us they do not comment on pending litigation.