That theory sounds like hearsay...
...Also, with all of this lying going on, and evidence to the contrary that implicates Thoresen, who would believe whatever the powers that be says about DNA? They could just be lying, too.
Whether or not Collins was lying (and one way or the other he was), his handwritten and signed statements are certainly NOT hearsay. What he says could be used in any trial or appeal hearing. It is first hand, not something that he "heard" from another. He clearly states, "this is what happened".
What is significant about his statements (aside from the included tall tales regarding Arnold Davis) is that he ADMITS having known/met both Karen Sue Beineman and Alice Elizabeth Kalom just prior to their murders. He ADMITS having taken both for motorcycle rides. And he ADMITS to sexual acts which put his DNA on/in their bodies.
Of course, he tries to mitigate that by saying that it was all consensual and innocent, and that he never killed them - it was (according to Collins) Arnold Davis who stepped in at the last minute and committed BOTH murders on separate occasions.
Yeah, that's the ticket - it was Davis - and poor Collins has innocently taken the rap for it all these years, because of his allegiance to his dear buddy Davis, and his dedication to protecting this "serial killer".
Furthermore, note that Collins ADMITS to having assisted Davis with the cleaning up of the Leik basement and to helping him dump Karen's body in the ravine. In effect, Collins ADMITS to being an accessory to first degree murder, both before and after the fact. He only comes short of actually admitting the whole truth.
Collins stated that it was Davis who was seen running past the body dump site on the night of the police stake out.
Collins has yet to say anything that would implicate Thoresen in any of the murders.