Details of Disappearance
Shirley was last seen in Broken Bow, Oklahoma on May 23, 1975. She spoke to her sister on the phone and said was leaving on a trip with her boyfriend, Alex "Ace" Banning Sr. Shirley has never been heard from again. Her yellow 1967 Opal Kadet was found abandoned in the parking lot of the Hilton Inn. Inside were some undergarments, two pairs of shoes, and some flowers Shirley had planned to place on graves for Memorial Day.
Alex had a history of abusive behavior towards Shirley and his ex-wife says he abused her also. Shirley allegedly told her sister that if she ever disappeared, Alex had probably murdered her. Authorities have long considered Alex a suspect in Shirley's case, but no charges were filed against him. He died of a heart attack in 1993, while in prison for an unrelated rape. A photo of him is posted with this case summary.
Shirley has never been found. An informant told police Alex had killed her because she was going to reveal incriminating information about one of his family members. Her body may have been dumped in a well in Etna, Arkansas, on property owned by Alex's family.