The heart attack that killed Nigeria's leading political prisoner Tuesday makes it easier for that country's military leaders to hold new elections -- but the circumstances of Moshood Abiola's death will raise suspicions. "When a political prisoner collapses and dies of a heart attack during a meeting with U.S. officials, questions are bound to be asked," says TIME U.N. correspondent William Dowell. "An autopsy will be important to clear up doubts over whether he was assassinated."