UNWITTING VICTIM: At a retreat on November 19, 1953, Sidney Gottlieb slipped LSD into Olson's drink without his knowledge. This was a deliberate experiment on an unwitting subject.

PSYCHOLOGICAL CRISIS: After being drugged, Olson experienced a severe psychological crisis. He told colleagues he had made"a terrible mistake."The nature of his distress suggested he may have learned disturbing information about biological weapons use.

THE FALL: On November 28, 1953, Olson allegedly ran across a hotel room and crashed through a closed window shade and glass, falling 13 stories to his death. A CIA agent was in the room.

OFFICIAL COVER-UP: The CIA told his family it was suicide from work stress. The truth about the LSD dosing was hidden for 22 years until the Church Committee investigation.

EXHUMATION EVIDENCE: In 1994, Olson's body was exhumed. Forensic pathologist James Starrs found a cranial injury inconsistent with falling and consistent with a blow to the head before the fall.

MURDER THEORY: The forensic evidence, coupled with Olson's potential knowledge of U.S. biological weapons use in Korea and his expressed desire to quit, suggests he was killed to prevent him from talking.

FAMILY'S FIGHT: Olson's son Eric has spent decades investigating his father's death. The family received a settlement and apology from President Ford in 1975, but believe the full truth remains hidden.

SYMBOLIC CASE: The Olson case represents the willingness of intelligence agencies to kill Americans to protect secrets. His death was neither investigated nor prosecuted.