A Memphis man is behind bars charged with killing his four-year old step-grandson.
Police charged 62-year-old Robert Matthews with first-degree murder Saturday, after they say he became angry with Diavion Staten for playing with his tools.
Matthews initially told police that Staten shot himself, but police say the shooting was not an accident.
When police arrived at the home, the boy was in critical condition with a gunshot wound to the head.
He was taken to the hospital, where he later died.
Investigators are waiting for a cause of death ruling at this time.
Family members say Matthews suffers from dementia.