Have you tried local public library to see if they have anything on the killing? Either a local published works, or maybe an unpublished manuscript. Libraries sometimes have files on local items of historical interest. Or, Cooke County Heritage Soc., P.O. Box 150, Gainesville, TX 76240. Or, Cooke Co, TX usgenweb site? Some of the counties for the usgenweb project have lookups, and people will check various items. Or you can place a query on that site. This site will not show URLs, so if you have not tried usgenweb project, email me direct, and I will be glad to give it to you.