BOISE – A federal judge has cleared the way for serial killer Joseph Duncan’s execution for the 2005 kidnapping, torture and murder of a 9-year-old North Idaho boy, ruling that Duncan was mentally competent when he gave up the right to appeal his death sentence. There still could be further appeals, but U.S. District Judge Edward Lodge’s ruling Friday is a key step toward execution for Duncan, who’s been sentenced to death three times over and has been linked to the murder of children and adults. Lodge wrote in his 66-page ruling that he’s “presided over numerous competency hearings in my 50 years on the bench. While these decisions many times are difficult and hard to make because of the consequences that follow, the Court is firmly convinced that the conclusions stated in this order are correct.”