United Airlines Flight 629 - Investigation

Investigation

Investigators determined that the aircraft began to disintegrate near the empennage, or tail, and that the aft fuselage had been shattered by a force strong enough to cause extreme fragmentation of that part of the aircraft. The explosion had been so intense that investigators thought it unlikely to have been caused by any aircraft system or component. There was also a strong smell of explosives on items from the No. 4 baggage compartment.

Suspicions that a bomb had been placed in luggage loaded aboard the aircraft were fueled by the discovery of four pieces of an unusual grade of sheet metal, each covered in a gray soot. Further testing of the luggage from No. 4 compartment showed that each piece was contaminated with chemicals known to be byproducts of a dynamite explosion.

The FBI, certain that the aircraft had been brought down by a bomb, performed background checks on the passengers. Many had purchased life insurance at the airport just before boarding. One such insuree was Daisie Eldora King, 53, a Denver businesswoman who was en route to Alaska to visit her daughter. When agents identified her handbag they found a number of newspaper clippings containing information about King's son, John Gilbert Graham, who had been arrested on a forgery charge in Denver in 1951. Graham, who held a grudge against his mother as the result of an unhappy childhood, was the beneficiary of both her insurance policies and her will. Agents also discovered that one of Mrs. King's restaurants, the Crown-A Drive-In in Denver, had been badly damaged in an explosion; Graham had insured the restaurant and then collected on the insurance following the mysterious blast.

Agents subsequently searched Graham's house and automobile and found wire and other bomb-making parts identical to those found in the wreckage. They also found an additional $40,000 in insurance policies; however, Mrs. King had not signed either these policies or those purchased at the airport, and they were therefore worthless. Graham told agents that his mother had packed her own suitcase, but his wife, Gloria, revealed that Graham had wrapped a "Christmas present" for his mother on the morning of the day of Mrs. King's ill-fated flight.

Faced with the mounting evidence and discrepancies in his story, on November 13, 1955, Graham finally confessed to having placed the bomb in his mother's suitcase, telling the police:

"I then wrapped about three or four feet of binding cord around the sack of dynamite to hold the dynamite sticks in place around the caps. The purpose of the two caps was in case one of the caps failed to function and ignite the dynamite ... I placed the suitcase in the trunk of my car with another smaller suitcase...which my mother had packed to take with her on the trip."