30 years unsolved
In a remote metal cottage in mountains of Rwaanda, American naturalist Dian Fossey was found dead in Dec., 1985. The 53-year-old author and TV personality was found hacked to death by a machete, her face split diagonally.
Beginning in 1967, Fossey crusaded to protect the gorillas of central Africa from poachers. She called the rare mountain gorillas a misunderstood and gentle species.
The dedicated scientist named the gorillas, learned to mimic their sounds and built a cemetery near her cabin for those that were killed by poachers.
Though Fossey's eccentric behavior sometimes embarrassed the wildlife community and Rwandan government, her research portrayed the mountain gorilla in a new light - as an affectionate, friendly animal.
The following year, the government of Rwanda accused and convicted Wayne McGuire of the murder in absentia. McGuire had spent the past year studying with Fossey as her research assistant.
Having returned to the U.S., McGuire publicly declared his innocence, suggesting that poachers or Rwandan officials wanted Fossey dead.
Her attacker was never identified and her murder was never solved.