In March 1742, British naval officer John Byron witnessed a murder on the western coast of South America. Both Charles Darwin and Robert FitzRoy seized upon Byron's story a century later, and it continues to play an important role in Darwin scholarship today. This essay investigates the veracity of the murder, its appropriation by various authors, and its false association with the Yahgan people encountered during the second voyage of the Beagle (1831–1836). Darwin's use of the story is examined in multiple contexts, focusing on his relationship with the history of European expansion and cross-cultural interaction and related assumptions about slavery and race. The continuing fascination with Byron's story highlights the key role of historical memory in the development and interpretation of evolutionary theory.