A long-haul truck driver whose profession gave him mobility across multiple European countries over more than three decades, Eckert used that freedom to carry out killings that went undetected for years. His victims were overwhelmingly women in vulnerable circumstances, and the full scope of his crimes remains uncertain — his suicide the day after his birthday cut short proceedings that might have clarified cases still open in Italy, the Czech Republic, and elsewhere.

The Godeffroy trading empire's Pacific expansion placed it at the center of two of the nineteenth century's most consequential colonial dynamics: the extraction of island resources through blackbirding — the coercive recruitment of enslaved labor — and the supply of arms to warring factions in exchange for vast tracts of land. At its height, the network stretched from Hamburg to Samoa, Chile, and China, operating with a fleet of over a hundred vessels and the tacit backing of the German imperial government, which used the company as an instrument of colonial policy.

She operated for decades as a village herbalist and poisoner, supplying arsenic compounds to clients who sought to rid themselves of unwanted husbands, relatives, and neighbors — making her complicit in a network of domestic killings that spanned generations in rural Vojvodina. What distinguished her case was less the act of killing than the scale of facilitation: estimates of deaths linked to her trade run into the hundreds. She was tried and convicted in her nineties, having outlived most of her victims and, reportedly, most of her accusers.

Bittrolff drew renewed attention during one of the more complex unsolved serial murder investigations in recent American history, though he was ultimately convicted on two counts stemming from the deaths of Rita Tangredi and Colleen McNamee in the 1990s. The case against him was built largely on DNA evidence, and his conviction came more than two decades after the killings.

Over roughly three and a half months in 1986, he targeted elderly residents across several London boroughs, gaining entry through unsecured windows and leaving little immediate evidence — several deaths were initially recorded as natural causes. The victims ranged in age from 67 to 94, and the consistency of method across the attacks pointed early to a single perpetrator, though the pattern took time for investigators to establish. His convictions were later reduced to manslaughter on grounds of diminished responsibility, and psychiatric assessment found he had likely been living with chronic schizophrenia and antisocial personality disorder since adolescence.

His leadership of the Santa Rosa de Lima Cartel coincided with a period of severe cartel warfare in Guanajuato, as the CSRL clashed violently with the Jalisco New Generation Cartel for territorial control — contributing to the state becoming one of Mexico's most blood-soaked conflict zones. What distinguished his operation was its foundation in fuel theft rather than drug trafficking alone, tapping into the black market for stolen petroleum as a primary revenue stream before his capture in 2020.

Wiese operated at the intersection of desperation and opportunity, exploiting the limited options available to women with illegitimate or unwanted children in late nineteenth-century Hamburg. Her crimes followed a pattern rooted in financial fraud — collecting fees for adoptions she never arranged — but escalated to systematic poisoning when the deception became unsustainable. The inclusion of her own grandchild among the victims marks a particular threshold in the case's history.

What began with the opportunistic sale of a lodger's body escalated into a calculated murder operation supplying Edinburgh's anatomy trade. Hare distinguished himself from his partner Burke by turning Crown's evidence, escaping execution in exchange for testimony that sent Burke to the gallows. The case exposed the lethal consequences of a legal framework that could not keep pace with scientific demand, and directly prompted the Anatomy Act of 1832, which reformed how cadavers could be lawfully obtained.