An interesting theory ngll
One theory that I think is at least worth considering is that Bryan was involved, but not necessarily the person who physically carried out every attack. He could have been the driver, helped plan it, supplied the knife, or brought someone else there. The biggest reason this idea even comes up is that the evidence connecting Bryan to the actual inside of the house is surprisingly narrow. His DNA was found on the knife sheath beside Maddie, but investigators did not publicly establish victim blood or hair in his car, apartment, or elsewhere tied directly to him.
That creates an interesting possibility. If the knife and sheath belonged to Bryan, his DNA being on the sheath makes complete sense even if another person was holding the knife that night. At the same time, the white Elantra and Bryan’s phone movements strongly suggest he was involved in the trip to Moscow, but the surveillance never clearly shows Bryan himself getting out at King Road or proves that he was the only person inside the car. So it is possible to imagine Bryan driving while someone else enters the house.
The second person being someone familiar with the victims would also explain a few things that otherwise feel strange. The house had an unusual layout, yet the attacker seems to move through it pretty efficiently, using the rear sliding door and heading toward the upstairs bedrooms. Someone who had been there before would already know where people slept, which entrance was normally used, and how to move around without wasting time.
The “I’m going to help you” statement Dylan reported hearing is also interesting under this theory. If Xana saw a complete stranger dressed in black with a mask, that sentence sounds bizarre. But if the person approaching her was somebody she recognized, or somebody who at least looked familiar enough not to immediately scream and run, telling her “it’s okay, I’m going to help you” could have been a way of keeping her calm for a few extra seconds. That does not prove she knew the attacker, but it fits more naturally if there was some familiarity.
There are also unidentified male DNA findings in the broader evidence, including DNA associated with Maddie’s fingernails and a male blood profile on a handrail. None of those have been shown to belong to another killer, especially because 1122 was a busy college house where lots of people had been inside. Still, if you are specifically testing whether a second person was involved, those are exactly the kinds of things you would want explained instead of automatically dismissing them.
The biggest problem with this theory is that there is still no clear link between Bryan and this hypothetical second person. There are no publicly established messages, calls, payments, mutual plans, or surveillance showing another person entering or leaving with him.
So I would not say the evidence shows there were two people. I would say something narrower: the evidence strongly suggests Bryan was involved, but some gaps leave open the possibility that his role was not exactly what people usually assume.