What distinguished Ryan from other career criminals of his era was the degree to which he manipulated not just victims but institutions — parlaying a carefully constructed prison persona into a cause célèbre for Canadian penal reform, only to resume his criminal life upon release. His story became a cautionary episode in the history of rehabilitation advocacy, illustrating how public sympathy, once mobilized, can be systematically exploited.

As deputy and chief enforcer for Raffaele Cutolo's Nuova Camorra Organizzata, he operated at the intersection of organized crime, political negotiation, and possible state intrigue — helping secure the release of a kidnapped politician while allegedly maintaining leverage over the officials involved. His suspected role in the death of financier Roberto Calvi places him at one of the more opaque nodes of 1980s Italian criminal and institutional life. His assassination in 1983 proved a hinge point: it signaled the collapse of Cutolo's political protection and accelerated the consolidation of Campania's criminal landscape under rival forces.

Schmid's case became as notable for its social dimensions as for the crimes themselves — a charismatic figure who cultivated a following among Tucson teenagers in the mid-1960s, with knowledge of his actions spreading through that circle before authorities were ever involved. The Life magazine profile that followed his arrest turned him into a subject of national examination, raising uncomfortable questions about youth culture, complicity, and the distance between a community's surface and what moves beneath it.

O'Banion ran Chicago's North Side bootlegging operation during Prohibition with enough force and cunning to hold his own against the formidable alliance of Johnny Torrio and the rising Al Capone — a rivalry that helped define the era's gangland violence. His refusal to yield territory or honor underworld protocols made open conflict inevitable, and his 1924 murder in his own flower shop set off a cycle of retaliatory killings that left the city's criminal landscape fundamentally altered.