In 1991, a surveyor was convicted of killing his business partner on a remote stretch of Montana highway — a case built almost entirely on tire-track evidence and a single eyewitness. But when a graduate student digitizing decades-old land survey records for a university archive stumbled across handwritten field notes in the victim's own hand, dated the morning of the murder, the geography of the crime scene itself began to unravel the prosecution's timeline. Tonight, we follow the quiet, obsessive work of one defense investigator who spent eleven years proving that a dead man's measurements were more reliable than a living witness's memory.