The Clinton Police Department requested the assistance of the Oklahoma State Bureau of Investigation after a man was accused of killing his mother early Saturday morning.
Police found the body of 66-year-old Judy Mallin around 4:30 a.m. in Clinton.
Mullin was traveling with her son, Dennis Rigsby, who had just been released from an Oklahoma prison.
Risgby had served 17 years for manslaughter.
Authorities believe he is responsible for his mother's death.
Rigby is facing a first degree murder charge.