An Arizona man has been sentenced to 30 years in prison for the stabbing deaths of a teenager and her grandmother on the Fort Apache Indian reservation. Martyn Wallen pleaded guilty in July to two counts of second-degree murder. He was sentenced late last month to 20 years on one charge and 30 years on the other. A federal judge ordered the sentences to run concurrently. According to court documents, Wallen broke into a home to steal DVDs when he heard a cough and saw two females lying on a bed. He told investigators he grabbed a kitchen knife and repeatedly stabbed the grandmother. Her 15 year old granddaughter had rolled on top of her to try to protect her. Wallen was 17 at the time. He was tried as an adult.