If it wasn't tested, how does the Defense know there's DNA? There's only one way the Defense can claim there are three "unknown" samples of DNA: the lab found three unknown DNA samples. There's no way to know there are three DNA samples unless the samples were tested (they could be anything).
I think the jury will be smart enough to handle this if in fact the Judge says, "Hey, go ahead, mention the 3 unknown males." Then of course, there will be witnesses mentioning that many, many people had been in the house - but only ONE left his DNA on the covering of the murder weapon - and not only that, right inside the death scene. Near the bottom of a victim. And that same person (with a certain shoe size and certain toe lengths) stepped in victim blood and walked through the house. But no one can claim there are "three unknown males" sampled if the tests weren't already done. IOW, the State has a print-out of ACTG's (BILLIONS of letters per sample) which does not match anyone known to have been in 1122 King Road recently.
It's not just the DNA that points to Kohberger. However, it does seem to me that Kohberger must explain how his DNA got on the sheath. If, for example, somebody stole his sheath, it would have been wise for him to convey that information (through an attorney if necessary) to the investigation. And truly, if someone stole his phone and his car and drove them twice to Moscow and then southward and then back to Pullman, he could explain that he wasn't in it - but INSTEAD he says "Yep, I was out driving."
IMO. I also believe that LE had narrowed down the car make and model sufficiently to know that not everyone in the region had come forward and said, "Yeah, I drive a car like that, and I was out driving that night, but I did not do it."
IMO.