Hancock was murdered near Beef Creek/ White Bead Hill Ind.Ter.(Pickens Co now Garvin Co Okla).He was killed by a John Black. Witnesses were James Bovie(Boyce?) - M.Goss-J.Miller.
Bass Reeves- U.S.D.Marshall - took John Black in custody at Wewoka in Jan.ll, 1884.
John Black appeared before Stephen Wheeler in U S Court Western Ar. - Fort Smith Ar.
John Black's case was discharged Feb. 4, l884.

The copies sent to me by NARA in Fort Worth TX did not have any information on the reason for the murder or the reason why John Black was released.

I think there could be an article on this murder in the Cherokee Advocate or another newspaper of that area.
Any suggestion where I can find more information on this incident would be appreciated

The newspaper out of Fort Smith, AR, called the Fort Smith Elevator covered activities in that area during that time period. You may be able to access those on microfilm, perhaps through inter-library loan.