A long-haul trucker, Mendenhall used the mobility and anonymity of interstate routes to target victims across multiple states, with investigators linking him to a series of killings at truck stops in the South and Midwest. His case drew attention to the broader phenomenon of highway serial killings, a pattern law enforcement had been working to systematically document. The conviction in the Hulbert murder represented only one anchor point in an investigation that spanned several jurisdictions.

Her crimes occupy a singular place in criminal history less for their scale than for their method — the deliberate, domestic transformation of victims into household products. Operating in a small northern Italian town in the final years before wartime disrupted everything, she killed three women in quick succession, motivated in part by a belief that human sacrifice would protect her son from the dangers of military service. The matter-of-fact industrial quality of what she did afterward is what has kept her name in circulation for decades.

Over a span of months in 1993, Denyer targeted young women in suburban Melbourne, killing three within a geographically contained area — a pattern that generated sustained public fear before his arrest. The crimes were defined less by complexity than by their repetition and the vulnerability of those he targeted in ordinary, residential settings. His parole application was denied in 2023, and he remains imprisoned on consecutive life sentences.

A physician who rose to power on a populist platform, Duvalier built one of the Western Hemisphere's most repressive regimes, using a personal paramilitary force — the Tonton Macoutes — to eliminate political opposition through violence, disappearance, and terror. His consolidation of power was methodical: early democratic legitimacy gave way to rigged elections, a declared presidency-for-life, and the systematic dismantling of any institution that might check his authority. Estimates of those killed or forced into exile during his fourteen-year rule run into the tens of thousands.