Sekine operated through the mundane cover of a dog-breeding business, using the trust of ordinary commercial transactions to target and kill at least four clients over the span of a few months. The crimes were committed in partnership with his common-law wife, and the case drew significant attention in Japan both for the calculated exploitation of that trust and for the swift succession of killings within a single year.

His crimes unfolded across a single year, concentrated in the impoverished outskirts of Rio de Janeiro, where he targeted boys who were vulnerable to small offers of money or promises of help. What distinguished his case was the ideological framework he constructed around the killings — drawn from religious broadcasts he had followed for years — which shaped both his victim selection and his self-justification. He confessed immediately upon arrest and described his crimes in detail, providing investigators with accounts of fourteen murders committed between April and December 1991.

Operating in the mountains and forests around Banská Bystrica over a four-year span, Lupták carried out attacks that were separated by an intervening prison term for unrelated offenses — a pattern that underscores how incidental circumstances, rather than detection, interrupted his crimes. The case drew particular attention because one victim was buried while still alive, a detail confirmed at autopsy. His eventual capture came not through the murder investigation itself but through a separate break-in, after which he was identified from a composite sketch at the police station.

A successful Bordeaux merchant who built his commercial network through Protestant exile connections, Laffon de Ladebat expanded into the transatlantic slave trade from 1764, adding human trafficking to an already prosperous colonial trade operation. His career illustrates how merchant capital in the French Atlantic world frequently moved from wine and goods into the slave trade as the economic logic of the West Indies colonies took hold.

As chief of DOPS during Brazil's military dictatorship, Fleury became one of the most feared figures in the country's apparatus of political repression — overseeing interrogations, disappearances, and extrajudicial killings targeting dissidents and leftists. His effectiveness lay in operating at the intersection of state authority and sanctioned lawlessness, where institutional cover made accountability nearly impossible. The scale of harm attributed to him and the unit he led left a long shadow over Brazil's reckoning with that era.