How do police departments test mushrooms for psilocybin?
If you are asking if when they take a blood/urine/hair sample if
psilocybin can be detected;
The answer is yes. Psilocybin can be detected for just a little
over a week after ingestion. The catch is, it is a particular test.
On another note, most police law enforement agencies give a
lifestyle polygragh evaluation. You will be asked if you have ever
taken any illicit drugs. Psilocybin is a schedule one controlled
substance under federal law. Though they say answering truthfully
will not immediately bar you from employment, you should most
likely pursue another career path.