Interesting! That makes sense.In this case (and this is pure speculation), they probably got a tip about this guy and started by questioning him about the Delphi case. He probably denied denied denied, then they came at him with something like, "Look, we're pretty sure you've already killed somebody, your uncle."
Then, to build credibility for the denials of killing the girls, he admits to killing his uncle. Granted, he didn't actually think of it that way, but that's how the psyche works sometimes.
True! It sounds like if they would have asked him if he did it then it would have answered "Yes"Sounds like he has been a suspect all along, can't believe it took this long to trip him up and get a confession.