[cyncooper]

Is it just me or is it unusual for the same person that scientifically analyzes trace evidence to also visit various "crime scenes"?

I am getting the opposite impression. That cross contaminatin could not have happened as investigators did not go between van Dam and Westerfield homes at all. Others visited different scenes but on different dates, etc.

[Southflanknorthpawsis]

I think you missed the point. I was not necessarily talking about cross contamination. I was talking about INDEPENDENT labs versus the same person wearing various hats.

What do you suppose the reason is for emphasizing INDEPENDENT if it doesn't really matter? I'm just curious.