Operating across rural Switzerland over the course of six years, Peiry preyed on young hitchhikers in a methodical pattern of abduction, assault, and destruction of evidence that investigators would link to at least five confirmed killings, with eleven attributed to him in total. His case drew sustained national attention not only during the investigation but long afterward, resurfacing in Swiss public discourse in 2004 as a reference point in a referendum on how the state should handle violent offenders.

Operating in Lima over several years, Nakada carried out targeted killings against people he categorized as social undesirables, framing his violence as divinely sanctioned cleansing. His methods were methodical — homemade silencers fashioned from rubber slippers, a 9mm pistol — suggesting sustained premeditation rather than impulse. The case is further notable for the fraternal dimension: his younger brother later carried out a separate killing spree in Japan, raising questions about shared pathology within the family.

Known by the nickname "Grandpa Hassan," Usoyan rose through the Soviet criminal underworld to become what The Economist described as Russia's most powerful mafia boss — a distinction earned across decades of operation spanning Georgia, Moscow, Siberia, and Central Asia. His career traced the full arc of organized crime in the post-Soviet space, from regional enforcer to a figure whose reach extended across much of the former empire. He survived multiple assassination attempts before eventually being killed by a sniper in Moscow in 2013.

Chevalier occupies a singular place in French legal history as the last man to hold the office of chief executioner before capital punishment was abolished in 1981 — making the two guillotinements he carried out as Monsieur de Paris the final judicial executions in the country's modern era. His career, which began in 1958 as an assistant and ran through a period of declining use of the guillotine, ended not through any controversy but through legislative abolition under Mitterrand. The quiet arc of his later life — retirement, interviews refused, a printer's trade — reflects a role that was at once bureaucratic and irreversible.

One of the architects of Murder, Inc., he operated at the intersection of organized crime's most powerful factions during the mid-twentieth century, bridging Jewish and Italian criminal networks at a national scale. His capacity for personal violence — he worked extensively as a hitman — coexisted with a talent for large-scale enterprise, most visibly in his role shaping what would become Las Vegas. That combination of brutality and vision made him one of the more consequential figures in American organized crime history.