What distinguished Matsunaga was not merely the violence but the mechanism behind it — sustained psychological control over victims and their families that made them complicit in their own destruction. The Kitakyūshū case was considered so extreme that much of the Japanese press declined to cover it, a rare restraint that itself signals the nature of what was uncovered. Prosecutors described it as having no parallel in Japan's criminal history.

A nurse working in a pediatric and general care setting, Mori was convicted of administering a lethal dose of vecuronium bromide to a patient — a muscle relaxant with no legitimate therapeutic use in that context. The breadth of suspicion surrounding him, spanning victims from a one-year-old to an elderly woman, places him within the category of healthcare workers whose access to vulnerable patients and clinical knowledge enabled harm that was difficult to detect. His case drew attention in Japan to the systemic challenges of identifying and prosecuting medical killings, where cause of death can be obscured by the patient's underlying condition.

Few figures in American organized crime matched the longevity or behind-the-scenes authority that Accardo accumulated over his career. He navigated the treacherous internal politics of the Chicago Outfit for decades without succumbing to the violent ends that claimed so many of his contemporaries, eventually consolidating influence without holding formal leadership — a durability that set him apart from nearly everyone in his world.

His five-day killing spree in the summer of 1958 claimed four lives and an unborn child, triggered by something as small as the recovery of a ring. What makes Jarabo a figure of particular historical note is the combination of calculation and opportunism — methodically waiting for targets, eliminating witnesses, returning to a crime scene to sleep — alongside the almost casual recklessness that led to his arrest. His case drew wide attention in late Francoist Spain and remains one of the country's most studied criminal episodes of the twentieth century.

His twenty-four years as Iraq's head of state encompassed the Iran-Iraq War, the use of chemical weapons against Kurdish civilians at Halabja, the invasion of Kuwait, and the sustained repression of political opponents through state security apparatus. The scale of violence carried out under his authority — both in warfare and internal governance — places him among the most consequential leaders of the late twentieth century Middle East. He maintained power through a combination of patronage, ideological control, and systematic brutality that outlasted multiple wars and international sanctions.