On April 11, 1993, 58-year-old Donna Sundling, a female aerobics instructor, went on a hike with her husband, Robert Spangler, in the Grand Canyon. The trip was purportedly an effort to mend their strained marriage. During the hike, at a spot on Horseshoe Mesa, Donna fell from a height of 140 to 200 feet to her death. Her husband, Robert Spangler, calmly reported the incident to park rangers, claiming he had turned to adjust his camera and when he looked back, she was gone.
Despite Spangler's account of an accidental fall, Donna's relatives were immediately suspicious. They knew her to be agile and also to have a fear of heights, making it unlikely she would have been careless near a cliff edge. Adding to their suspicions, Spangler had his wife's body cremated before her mother could even travel to the scene. Although the circumstances were questionable, without conclusive evidence of foul play, her death was initially ruled an accident, and no charges were filed against Spangler at the time. For years, Spangler maintained his innocence, even appearing on television to discuss the dangers of hiking in the Grand Canyon as a grieving husband.
The truth about Donna Sundling's death remained a secret for years, intertwined with a darker family history. In 2000, facing a terminal cancer diagnosis, Robert Spangler began to confess his crimes to investigators. He admitted that on that Easter Sunday in 1993, the fourth anniversary of their meeting, he had pushed Donna off the cliff. His motive, as he stated, was dissatisfaction with their marriage due to a 'lack of similar interests.' His confession didn't stop there; he also admitted to the 1978 murders of his first wife, Nancy, and their two teenage children, crimes he had staged to look like a murder-suicide.
Following his shocking admissions, Robert Spangler was indicted by a federal grand jury for the murder of Donna Sundling. He pleaded guilty to first-degree murder in a federal court in Phoenix. As part of a plea agreement that spared him the death penalty, the terminally ill Spangler was sentenced to life in prison without the possibility of parole. He died in prison from cancer on August 5, 2001, finally bringing a close to the long-unsolved death of Donna Sundling.
