What are you complaining about here?
Should the cops not have field tests for suspected drugs?
Should they haul in everyone who is found possessing an unidentified substance?
The reason that leftists use sarcasm so much is that it so rarely leads to truth. I think that if you get in the habit of expressing your ideas in a straightforward manner then you will end up saying fewer irrational and false things, assuming that this is what you want.
As a degreed analytical chemist with 25 years in the pharmaceutical industry, I know that tests like this one are screening tests, and not definitive in any way.
To use them as definitive tests is unprofessional, ignorant and, hopefully, grounds for a lucrative lawsuit.
Any questions?