>> we can help you to determine whether this tissue is from the missing person by comparing the dna from the tissue to the family members and the children and the mother of the person who is missing. >> children get half of their dna from the mother and half from the father. by taking a dna sample from brad's wife, his four children and his mother, scientists could isolate brad's dna profile through a process of elimination. for this, scientists used an rflp test. at the time the most sophisticated dna test available. >> whose ever tissue sample that was was completely consistent with being the father of both sets of children and consistent with being the son of the mother of the missing person. >> next, scientists tested the