Johann Otto Hoch was born Jacob Schmidt in Germany around 1855 and arrived in the United States in the 1890s, leaving a wife and three children behind.
Over roughly fifteen years he married between forty and fifty women across Chicago, Cincinnati, St Louis, Milwaukee and elsewhere, under at least a dozen names. The method never varied: he answered or placed matrimonial advertisements, courted a widow or spinster of modest means at speed, married within weeks, obtained control of her savings, and left. A number of the women died shortly after the wedding of what was recorded as kidney disease or gastritis. The Chicago press called him the Bluebeard Murderer.
He was caught in January 1905 through impatience. He married Marie Walcker in Chicago in December 1904, she died within weeks, and he immediately proposed to her sister, who went to the police when he asked for money. The body was exhumed and found to contain arsenic. He was arrested in New York on January 30, 1905, wearing a fountain pen filled with arsenic.
He was tried for Marie Walcker's murder, convicted on June 23, 1905, and hanged at the Cook County jail on February 23, 1906. Fifteen or more of his wives are believed to have been poisoned; one was proved. He denied everything to the end.