Trying to make sense of DNA chat in episode 6 of Adam Shand's recent podcast

Hi all.

I just listened to this episode. What I couldn't make sense of was the DNA talk - does it still exist? Is there anything on record? If I'm understanding correctly, Shand says DNA collected at one of the Hampton crime scenes didn't match DNA from one of the 4 canonical crimes. Is that correct?

I'm a bit skeptical because, ordinarily, that would be a smoking gun, but he hardly refers to it all after it's mentioned the first time. What am I missing here?