Who Killed Mary Eula Sears?

From the start, the murder frustrated Abilene police. Eleven officers searched every room of Mary Eula’s house for clues, but all they found was the murder weapon, a bloody hunting knife that had no fingerprints on its ridged handle. Partly because the home’s ornately carved antique furniture had few smooth surfaces, only two usable fingerprints were found, and both of them belonged to Officer Berry. No hairs, no semen, and nobody else’s blood but Mary Eula’s.