Could non-disclosure agreements prevent criminals from snitching on each other, or to prevent legally obtaining proof of illegal operations?
I have two similar scenarios in mind:
- A group of bank robbers sign NDA-s to each other, so that if one gets caught, their testimony will be inadmissible due to being "fruit of the poisonous tree".
- An illegal gambling establishment signs an NDA with anyone who enters, so that any information gathered by law enforcement would be illegally obtained.
The question is: does the fruit of the poisonous tree doctrine extend this far, and are there any examples of criminals trying something similar?