In 1997, Coleman was arrested for DUI and convicted. In 2003, he was living in the very tiny southeastern town of Portal, Arizona (the location of Crystal Cave--I've camped and done some spelunking there). He went with his date Gail Chalker, her two sisters Annette and Carol, and Annette's fiance, Colby Rawson to the nearby town of Rodeo, New Mexico, for an evening of drinking at the Rodeo Tavern. Annette and Gail got into an argument over an air compressor that Annette wanted to borrow. Coleman and Gail and Carol Chalker returned to Portal at 10:30 p.m., and Rawson and Annette Chalker and her two children drove up to Coleman's home shortly before midnight to pick up the air compressor that was kept on the porch. She opened the door and called to her sister, and when the screen door slammed shut, Coleman and Gail Chalker were awakened. Coleman grabbed his .38 pistol, and the two of them left the bedroom and saw Annette Chalker in the entryway. Gail Chalker says that Annette charged them and was trying to grab her by the throat, and Coleman's gun fired, shooting a bullet into Annette's face below her left eye, killing her. Coleman said it was an accident, and Gail Chalker corroborated his story.
Coleman was indicted on charges of first-degree murder but was never prosecuted for lack of evidence. He was sued by the Chalker family for wrongful death, which was settled.
When asked about Coleman, Arizona Republican Party chairman Matt Salmon said, "I've never met the guy. This is the first time I've even heard about this guy. ... The Republican Party did not recruit him to run. ... I'm very discouraged about anybody who has a DUI in their background."
Coleman is a 1993 Rutgers University graduate who has worked in the Phoenix area since 1997 as a computer contractor for the state Department of Economic Security. He runs a consulting company called Candia Systems Associates. He grew up in Cochise County, where his family had a ranch. His stepfather was Wyatt Earp researcher Glenn Boyer, an amateur historian who has been charged with fabricating material in the book I Married Wyatt Earp, which billed Josephine Earp as the author and Boyer as the editor. That scandal first came to public view as a result of investigation by Tony Ortega, then of Phoenix's weekly New Times. Ortega went on to work at the Los Angeles New Times (now defunct) and has written several in-depth investigative pieces about the Church of Scientology.
Coleman's mother (and Boyer's wife) is Western novelist Jane Candia Coleman.
(Most of the above is from the Arizona Republic story on Coleman.)