The Axman of New Orleans specialized in killing grocers of Italian descent in the 1910s, apparently to promote jazz music. Dorothea Puente was a little old landlady who murdered her tenants, but kept cashing their government checks. The Manson Family terrorized California in the 1960s, as did the Hillside Stranglers a decade later. Twelve serial murder cases, occurring in eight decades between the 1890s and 1990s, had one thing in common: significant...