In the late 19th century, Europe’s expanding urban populations and advances in forensic science brought greater attention to violent crime, including cases of poisoning that targeted private domestic settings. One of the earliest and most publicized cases often cited in historical literature involves Franz Müller (sometimes referenced in period press reports), who was executed on March 14, 1896, after conviction for the deliberate poisoning of multiple victims. The case attracted sustained media and legal interest at the time and contributed to evolving methods for detecting and prosecuting arsenical and other toxic substances. Background and investigation Reports from the period indicate that the suspected poisonings occurred in domestic contexts, where food and drink were the common vectors. Investigators relied on emerging analytical chemistry techniques to detect poisons in exhumed remains and preserved samples — a field that had been developing since the mid-19th century with the establishment of more systematic forensic toxicology protocols. Contemporary newspaper accounts emphasized both the intimate nature of the crimes and the technical challenges of proving poisoning beyond a reasonable doubt. Trial and conviction The trial drew public attention, in part because poisoning cases were often treated as crimes that violated the sanctity of the household. Prosecutors presented chemical analyses and witness testimony; the defense contested the interpretation of laboratory findings and the motives ascribed to the accused. After deliberation, the court convicted Müller of multiple counts related to poisoning, and he received capital punishment. The execution on March 14, 1896, marked the legal conclusion of a highly publicized proceeding. Impact and legacy Historians treating late-19th-century criminality and forensic practice cite the case as one of the episodes that spurred improvements in toxicological methods, chain-of-custody standards, and medico-legal collaboration. The publicity around the trial also heightened public anxiety about domestic poisoning, influencing both popular culture and policy discussions about food safety, household oversight, and criminal investigation. Caveats and historiography The label “first known serial poisoner” should be used cautiously. Poisoning with criminal intent has a long documented history across cultures and eras, and other earlier cases of multiple poisonings are recorded in historical and legal sources. What made the 1896 case notable was the combination of multiple confirmed victims, a publicized modern trial, and the application of contemporary forensic techniques. Sources from the period include newspaper reportage, court records where available, and subsequent historical analyses of forensic toxicology; specific archival citations vary by language and jurisdiction. Where details differ among accounts, historians note discrepancies in victim counts, motive attribution, and technical laboratory interpretations. Conclusion The March 14, 1896 execution closed a landmark case in the public and professional history of poisoning investigations. While it is inaccurate to claim it established the very first instance of serial poisoning in all of history, the case remains significant for its role in advancing forensic toxicology, shaping legal responses to domestic murder by poison, and influencing public perceptions of safety within the home.