San Francisco police say 76-year-old Mark Personette was arrested this week in connection with the 1978 death of Marissa Harvey.
The 15-year-old girl from New York was visiting the city when her body was found in a park.
Police said detectives used the best available technology at the time and exhausted every lead, but the probe went cold.
In October 2020, they reopened the case and determined Personette to be a suspect using “advanced investigative methods.”
Detectives say Personette may be a suspect in other unsolved homicides involving young women.