Cuban leader Fidel Castro

In this May 1, 1980 file photo, then Grenada's Prime Minister Maurice Bishop, center, is flanked by Cuba's leader Fidel Castro, right, and Nicaragua's President Daniel Ortega in Havana, Cuba. A haunting Cold War mystery is getting a fresh look on the Caribbean island of Grenada, where the body of the Marxist prime minister is still missing nearly 30 years after he was executed during a bloody coup that sparked a U.S. invasion. (AP Photo/File)

In this May 1, 1980 file photo, then Grenada's Prime Minister Maurice Bishop, center, is flanked by Cuba's leader Fidel Castro, right, and Nicaragua's President Daniel Ortega in Havana, Cuba. A haunting Cold War mystery is getting a fresh look on the Caribbean island of Grenada, where the body of the Marxist prime minister is still missing nearly 30 years after he was executed during a bloody coup that sparked a U.S. invasion. (AP Photo/File)