My mother was shot in Sept. 1975 can we sue the state for negligence or has the statue of limitations been reached?

My mother was shot in 1975. The gentleman that committed this crime was an escapee from the NC Dept of Corrections. He had prior to this incident pled guilty to manslaughter and somehow escaped custody. This man was a stranger to my mother and due to the states negligence in keeping this monster behind bars he has ruined her life. She is a paraplegic from the waist down with limited use of her right hand. Currently this man is serving a life sentence due to the state releasing him on probation and him committing a similar crime to another woman. He is labled as an habitual felon. Any thoughts comments will be gladly appreciated.