 In all, Duncan has been convicted in Idaho for kidnapping and murdering the three victims in Coeur d'Alene, for which he was given six life sentences; in federal court for kidnapping Shasta and Dylan Groene and murdering Dylan, for which he was given three death sentences and three life sentences; and in the state of California for kidnapping and murdering Martinez, for which he was given two life sentences.Duncan has a long history as a violent sexual predator.He committed his first recorded sex crime in 1978 in his hometown of Tacoma, Washington, when he was 15 years old.