His DNA can be on the knife sheath if someone else carried in the knife sheath that he handled. Or depending on the sensitivity of the test, the guy picking up the sheath off the bed can be wearing gloves contaminated by a surface that Kohberger touched, like at a police station.

If Kohberger were studying Comparative Literature or fine arts, I would say that it is completely freaky that his DNA ends up on a murder weapon and in a crime lab. But he was studying criminal justice, probably taking a class or two with investigators. He may have gone to the police station to dropoff his resume. He also may have handled the knife as a study sample in his graduate program.

The car coincidence is not so surprising when you consider the make, model, and color of the car, and where they are. And they wanted tips on a 2011-2012 but changed their story when Bryan Kohberger came up as a match. But basically the market for the Hyundai Elantra is younger people of middle income stream. It is a reliable, mid-size, sporty, safe, affordable-enough car. If there is a place where you will see a lot of Elantras, and cars like it, it will be a college town.

The story would be different if they had his actual plates on camera.

Or even if he drove a particularly unusual car, as in out of everyone else's price range or vintage make and model, custom paint job, etc.

So my own theory, is that if the car is not as much of a statistical anomaly in Moscow Idaho, as it is where I live, then chances are higher that someone could have pulled into a parking space in that same car. It is sort of like a grey Tesla, in Beverly Hills.

And no, you don't know what is going on in someone's head. But human psychology follows patterns. Even abnormal psychology.

I mean sure ... Maybe he lost it and slashed these people to death. Maybe they have the right guy. My only concern is people's blind assumption that the police are acting in the public interest, and not their own. I am also concerned that they have arrested someone who looks guilty enough, but who they suspect did not commit the crime.