That's disturbing! Why is that?

Because it wouldn't pass.

I hoped that wouldn't be the answer :(

this is nonsense.

there are certainly a number of forensic fields which are garbage.

other portions are fine, and are effectively analytical chemistry applied to legal cases. are you aware of a lot of double blind studies in analytical chemistry? what would that even mean?

How much of the conclusions drawn from these investigative techniques are justified entirely by analytic chemistry, and how much goes beyond that? Using an example from a related article, there's a substantial difference between being able to say what's the chemical element composition of a particular bullet and being able to identify the particular manufacturing facility and batch it came from. The latter relies on a whole lot of assumptions about the ammunition industry.

>what would that even mean?

I gave an example at the top level comment. Apply the test (blind) to known innocent samples too, and see whether it implicates them.