very remote area, the northwest side of tucson and pima county.ear the same road, but 20 miles from where jr lived. way back in october of 2003, not long after marilyn and renee were killed, hunters found a partial human skull here. kelly anderson: this is a high trafficked area for undocumented border crossers. and unfortunately, many in the summertime in the hot summers of arizona do not make it and perish in this area. dennis murphy (voiceover): the medical examiner's office in tucson runs a unique program to identify such remains. but it takes time. so a small portion of the cranium was removed for dna testing at a later date, much later. eight years later in february of 2011, we finally get a dna match back from that skull that was found in 2003. and it is a positive match for linda watson. dennis murphy (voiceover): suddenly, the skull was a big priority. there was no sign of trauma, no evidence of how she died. still, 11 years after linda watson disappeared, at last, here was proof she was no longer alive. that's when you have a case. that'