There was only JBR's blood in the panties. The intruder DNA was mixed with her DNA, but there was NO other blood in the panties or anywhere else that did not belong to JBR. That foreign DNA could easily have gotten mixed with hers if she put her hands on a toilet seat or toilet handle, or doorknob in the White's home (or even her own home) and then, because JBR was known to dislike washing her hands (PR's own admission), transferred the foreign male skin cells to her own clothes. There were kids over playing Christmas Day in the R home- there were lots of people in that home for the R party on the 23rd. Every male known to be in the R home since the 23rd and at the White's that day, including children, needs to be matched to that "foreign male" DNA. DON'T call it the "killer's" DNA. It could belong to someone who was in either home in the days before the murder.