Her crimes unfolded quietly across the drawing rooms and sickbeds of Prussian society, with arsenic administered under the guise of care — medicines, soup, plums. What makes Ursinus historically significant beyond the killings themselves is the forensic reckoning they prompted: the effort to prosecute her pushed chemists to develop rigorous methods for detecting arsenic in exhumed remains, work that directly influenced the emergence of toxicology as a forensic discipline.

Within a span of roughly eight months, he carried out four murders in the Santiago Metropolitan Region, a spree that culminated in the killing of a police commissioner and prompted Chilean courts to declare him the country's most wanted fugitive. The targeting of a senior law enforcement official distinguished his case from typical criminal proceedings and drew sustained national attention. He was eventually captured and imprisoned, having committed his first murder at nineteen.

His method was clinical and nearly invisible — insulin administered in lethal doses, producing deaths that initially resembled natural causes. The decade-long span of his confirmed killings, combined with suspected additional victims, reflects how long such a technique could evade detection before forensic medicine caught up. His conviction marked a legal and scientific threshold, establishing for the first time in the United States that insulin could be prosecuted as a murder weapon.

Potier's career spans two of the era's most legally and morally contested maritime practices — privateering during the Napoleonic Wars and slave trading during the Bourbon Restoration — making him representative of a class of French seafarers who moved fluidly between state-sanctioned violence and commerce in human beings. Operating out of Saint-Malo's deep privateer tradition, he served under Robert Surcouf and eventually commanded his own vessels, capturing warships and merchantmen across the Indian Ocean. His later arming of the slave ship Africain and the transport of enslaved people from Guinea to Martinique placed him squarely within the illegal trade that continued after France's nominal abolition of the slave trade in 1815.

Operating across two Soviet cities over roughly a year, Almazyan committed a series of sexual assaults and three murders before his capture — a case that remained largely obscured within the Soviet state's tight control over public information about violent crime.

His act of political violence came at a moment of economic dislocation and ideological radicalization — a combination that shaped many of the era's most consequential figures. The assassination of President McKinley in September 1901 elevated Theodore Roosevelt to the presidency and accelerated a federal crackdown on anarchist movements in the United States. Czolgosz was tried, convicted, and executed by electric chair within weeks of the shooting, a pace that reflected both the era's judicial urgency and the depth of public alarm.

A celebrated actor who turned a moment of national exhaustion — Lee's surrender just days prior — into the site of a calculated political killing, Booth carried out what had begun as an abduction plot and became a coordinated, if partially failed, attempt to decapitate the Union government. His shot at Ford's Theatre on April 14, 1865, was the only piece of the conspiracy to fully succeed, ending Lincoln's life the following morning. The act reverberated far beyond the moment, reshaping Reconstruction and the trajectory of postwar America in ways its perpetrator never lived to witness.