Skiatook Man Sentenced In Great-Grandmother's Stabbing

A man who stabbed his great grandmother over doing the dishes will spend the rest of his life in prison.

Michael Stanley pleaded guilty to murder Wednesday.

2/12/2014 Related Story: Affidavit: Skiatook Murder Suspect Says He Killed Grandma Over Doing Dishes

In 2014, the then 19-year-old stabbed and killed his great grandmother before killing his little sister who was the only witness.

He's already serving a life sentence for his sister's murder.