Born to poverty in Cleveland, Mississippi, Robinson was arrested by hometown authorities in 1918, on charges of mailing obscene letters to local women. He escaped from custody en route to jail, and made his getaway despite a bullet in the shoulder. Eight years later, when decapitated women's bodies started turning up around Michigan City, police suspected Robinson alias "James Coyner" - of multiple murder. Four severed heads were found at a house he once occupied, in Ferndale, Michigan, but Robinson had moved on by that time, convicted and sentenced to prison for grave-robbing in Indiana. Interrogated by Michigan authorities in jail, Robinson played dumb, and the existing evidence proved insufficient to support a murder charge.

Paroled in July 1934, Robinson - as "Coyner" returned to Cleveland, Mississippi, and picked up his old hobby of writing obscene letters. One was mailed to an Indianapolis woman, the incorrect address identical to a recent misprint in an Indianapolis newspaper. Postal inspectors were still scouring the paper's subscription list when Robinson claimed two more victims, close to home.

On December 8, 1934, Aurelius Turner and his wife were shot to death in Cleveland, the woman's body mutilated with chunks of flesh sliced off and carried away by the killer. A month later, federal authorities traced poison-pen artist "James Coyner" to a post office box in Shaw, Mississippi, and officers were waiting when he came to get his mail on January 12, 1935. Robinson went for his .38, but the deputies were faster, and he surrendered in the face of superior firepower. A search of his pockets and lodgings revealed more obscene letters, a packet of human hair in Turner's color, and strips of human flesh, salted and cured like beef jerky.

In custody, Robinson freely confessed to the murders; he also admitted ownership of the heads found in Michigan, but claimed they were trophies secured during various grave-robbing expeditions. The prisoner offered no motive for his actions, but as the local newspaper proclaimed, Robinson "admitted that he was a sex pervert, which is considered to be the underlying cause for the crime."