Robert Spangler (January 10, 1933 – August 5, 2001) was a serial killer who came into the spotlight following the murders of his first wife, son, daughter, and his third wife.
Spangler was raised in Ames, Iowa, where a laboratory at Iowa State University is named after his father, a civil engineer.
On the morning of December 30, 1978, in Littleton, Colorado, Robert Spangler lured his wife, Nancy, into the basement with the promise of a "surprise." He then shot her in the head with a .38 handgun. Going upstairs, he shot his teenage children, Susan and David. David was slow in dying, so Spangler finished him off by smothering him with a pillow. Spangler had cunningly framed the crime scene, making it appear that his wife had shot their children and then herself.
In April 1993, when Spangler's third marriage to 59-year-old aerobics instructor Donna Sundling went sour, he took her hiking in the Grand Canyon and pushed her off a 140-foot (40 m) drop to her death.
Spangler was never directly implicated in his third wife’s death because it was ruled an accident. He drew national attention with interviews on several television shows. As a grieving husband, Spangler discussed his wife’s accidental death and the dangers of hiking in the Grand Canyon. Spangler continued to backpack the Canyon with a variety of partners several times a year.
After the death of his third wife, Spangler reestablished contact with his second wife, who moved back into his Colorado home and died of a drug overdose in 1994. This death was not investigated by law enforcement.
Spangler confessed to investigators in 1999. He described how, while married to his first wife, he fell in love with another woman, then shot his wife and two teenage children to be with her. Further, Spangler said he smothered his son with a pillow after shooting him because the bullet wound was not lethal. He strongly denied involvement in the overdose death of his second wife and refused to discuss the death in the Grand Canyon because he feared a civil lawsuit from his third wife’s grown children; however, he eventually confessed he pushed his third wife over the edge while she was facing him.
He was sentenced to life imprisonment without parole, dying of cancer while in federal prison.