Joseph Edward Duncan III (born February 25, 1963) is an American convicted serial killer and sex offender who is currently serving multiple death sentences and life sentences in conjunction with the 1997 kidnapping and murder of Anthony Martinez of Beaumont, California, and the 2005 kidnapping and murders of members of the Groene family of Coeur d'Alene, Idaho. He has also confessed but not been charged with the 1996 murder of two girls in Seattle, Washington. Born in Tacoma, Washington, Duncan's lengthy criminal history dates to when he was 15 years old. In 1980, he was sentenced to 20 years in prison for sexually assaulting a boy in Tacoma and as a result has spent most of his adult life in prison. He was paroled in 1994 but was returned to prison in 1997 for violating the terms of his parole. In May 2005, Kootenai County, Idaho authorities discovered the bodies of Brenda Groene, her boyfriend, and her 13-year-old son in the family home near Coeur d'Alene.
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