A discarded cigarette butt found near the body of a 24-year-old Vermont school teacher led to the cold case being solved 52 years later.
Police closed the decades-old file after finding evidence that an upstairs neighbour strangled Rita Curran after a having a fight with his wife and going for a "cool down walk".
Ms Curran was killed during a 70-minute window in July 1971, with her body found by her roommate in their shared bedroom in a house in Burlington, Vermont, US.
