DES MOINES, Iowa (AP) --- In the turbulent hours following President John F. Kennedy's assassination, many were uncertain about what to do, but medical examiner Earl Rose knew one thing: The shooting happened in Dallas, and it was his job to do an autopsy on anyone slain in the city.

Rose stood in a doorway at the hospital where Kennedy's body was taken on Nov. 22, 1963, in a vain attempt to block Kennedy's aides as they removed his coffin. The Secret Service and first lady Jacqueline Kennedy prevailed, and the president's body was flown to Bethesda Naval Hospital, where an autopsy was done by pathologists James Humes and Thornton Boswell. Their findings have been used to support an array of conspiracy theories about Kennedy's death.

Rose, who died Tuesday at age 85, believed many of those theories wouldn't have gained traction if he had been able to do his job. He told The Associated Press in 2003 that he and his staff should have done the exam.

"We had the routine in place to do it ... it was important for the chain of evidence to remain intact," Rose said. "That didn't happen when the body was taken to Bethesda."

Rose's widow, Marilyn Rose, said her husband wasn't angry about what happened at Parkland Memorial Hospital but did his best to follow the law.