As boss of the Philadelphia crime family through the 1980s, Scarfo presided over one of the most violent eras in that organization's history, relying on murder as a routine instrument of internal discipline and consolidation. His conviction on racketeering and first-degree murder charges came in part through the testimony of associates he had directed to carry out killings — a reflection of how thoroughly violence had permeated his operation. He died in federal custody, still serving a 55-year sentence.

His case is defined as much by institutional failure as by the crimes themselves — detained, having confessed, then allowed to escape during a police procedure, after which he killed again within weeks. The subsequent collapse of Russian-Ukrainian diplomatic relations meant he was never prosecuted for the full scope of what he is suspected of having done across more than eight years of violence. He remains imprisoned in Ukraine for the Kyiv murder alone, while the earlier cases in Leningrad Oblast remain formally unresolved.

The nickname history assigned her — "The Borgia of Maine" — reflects both the method and the intimacy of the harm: poison administered within her own household, to husbands and children alike, over the course of a decade. What makes Cowan's case historically notable is the sustained, domestic nature of the crimes, repeated across two marriages and into a third attempt before the pattern was recognized.

What distinguished Moreno González from many of his contemporaries was the deliberate fusion of religious identity with cartel structure — his organization issued quasi-scriptural texts to members and cultivated a messianic image among Michoacán's poor that served both as social glue and a recruitment tool. That ideological scaffolding helped La Familia Michoacana, and later the Knights Templar Cartel, maintain cohesion and local legitimacy in ways that pure enforcement rarely achieves. The result was an organization that operated simultaneously as a trafficking enterprise, a disciplinary cult, and a shadow welfare system.

The case drew sustained attention in Russia both for the age of the victims and for the extended period during which the 2005 murders went unsolved. Kruglov's final crime — the killing of a family member — led directly to his arrest and subsequent confession to all four killings. He was sentenced to life imprisonment in 2010.