just a question,
would you accept it if police found a match for that touch dna and it wasn´t any of the R´s ?
(not telling the R´s did not do it) just a question
Of course, what choice is there but to accept evidence?
As others have pointed out, this "someone else" doesn't necessarily have to be the killer, and if he is the killer, he didn't necessarily work alone.
For me, a match to the touch dna, and evidence that the "someone" was in Boulder at the time, would be reasonable doubt, and I could not find the Rs guilty, were I on a jury.