He was a fixture in Kenya’s wildlife scene, an eccentric American with a mass of white hair, known for meticulous work on the black-market prices of ivory and rhinoceros horn. Now he is the victim in a murder mystery.

The victim, Esmond Bradley Martin, was found dead in his home in Nairobi, Kenya’s capital, on Sunday, with a stab wound in his neck.

It is not clear if Mr. Martin, who was 76, was killed in connection to his strident views or his work. No doubt he had made many enemies, writing report after report that exposed the depth of the ivory and rhino horn trade across the world that has killed tens of thousands of endangered animals. His death sent shock waves through East Africa’s wildlife circles.

Kenyan police officials said they had yet to identify any suspects. Their leading theory is that Mr. Martin was killed in a robbery.