SAN JOSE, Costa Rica — Costa Rican authorities say they have detained eight suspects in the killing of an environmentalist who worked to protect leatherback turtles on the country's Caribbean coast.

Director of judicial investigations Francisco Segura says activist Jairo Moral Sandoval was killed two months ago by robbers who targeted visitors to the beaches in Limon province.

Segura said Wednesday that the motive in Mora Sandoval's killing was robbery and possibly the rape of three women who were with him.

Mora Sandoval was a volunteer with the nonprofit group Widecast, which protects turtle nests from poachers at Moin beach in Limon province.

His beaten body was found May 31 on that beach. His hands were tied behind his back and he had been shot in the head.