Beginning in the summer of 1903 the children of Italian immigrants were kidnapped, and dozens of innocent victims were gunned down. Bombs tore apart tenement buildings. Judges, senators, Rockefellers, and society matrons were threatened with gruesome deaths. The perpetrators' only calling card: the symbol of a black hand. The tabloid press heated ethnic tensions to the boiling point. Joseph Petrosino, a dogged and ingenious detective, and the all-Italian...