A witness identified Robert Chambliss, a member of the Ku Klux Klan, as the man who placed the bomb under the steps of the Sixteenth Street Baptist Church. He was arrested and charged with murder and possessing a box of 122 sticks of dynamite without a permit. On 8 October, 1963, Chambliss was found not guilty of murder and received a hundred-dollar fine and a six-month jail sentence for having the dynamite.
The case was unsolved until Bill Baxley was elected attorney general of Alabama. He requested the original Federal Bureau of Investigation files on the case and discovered that the organization had accumulated a great deal of evidence against Chambliss that had not been used in the original trial.