Operating in rural France during the mid-nineteenth century, he preyed specifically on domestic servants — women already vulnerable by circumstance, seeking employment far from familiar surroundings. The systematic nature of his method, luring victims with the promise of a position in a prosperous household, allowed him to continue undetected for years across multiple killings.

A long-distance lorry driver, Black used his work routes across the United Kingdom and into Europe as operational cover, abducting children from roadside locations spanning hundreds of miles — a geography that for years frustrated police efforts to connect the cases. The investigation that eventually led to his arrest and conviction is considered one of the most extensive in British criminal history. Suspicion has extended beyond his confirmed crimes to a range of unsolved child killings across Britain, Ireland, and continental Europe stretching back nearly two decades.

One of four men convicted in a murder carried out before the victim's family, Richley's case became part of a notable Arkansas capital punishment record. The crime's domestic setting and the number of perpetrators involved drew sustained legal attention, with proceedings continuing through appeals for years afterward.

Van Eyken carried out three strangulation murders within a five-month span in the early 1970s, targeting women in a concentrated area of Belgium. The attacks were marked by a distinctive signature behavior that gave rise to the nickname he became known by in the press and in later accounts of the case.

A celebrated commander of the Risorgimento, Bixio earned his place in the Italian national story through decades of battlefield courage — and earned his place here through the episode at Bronte in 1860, where his suppression of a Sicilian peasant uprising resulted in summary executions and a letter to his wife expressing contempt for the local population in terms that went far beyond military necessity. The gap between his public role as a liberator and his private brutality toward the people that liberation was meant to serve gives his career a particular historical weight. His actions at Bronte remain a studied case in how nationalist movements have managed the tension between emancipatory promise and authoritarian enforcement.