Originally Posted by
kartoffel
Makes sense for a large casino with professional security. For small time bars though, I wouldn't trust your typical 'bouncer' to handle detaining a suspect properly.
Unless they're waving a bag of dope for all to see, I assume you'd have already delayed them and let actual LE frisk them in accordance with the 4th Amendment prior to finding the "amount that would be more for dealing". Remember, you're not law enforcement. Anything YOU turn up prior to LEO's being on the scene is unlikely to be admissible evidence.
In Nevada, misdemeanor crimes only fall under the citizens arrest law if they involve endangerment of public safety, and the arrestor must have witnessed the actual crime.
Private citizens may make arrests for ANY felony that was committed or attempted in the presence of the arresting citizen. You also do not need to have been a direct witness, as long as you have proof of the crime (e.g. a robber fleeing a from store where you didn't see the actual robbery).
If you've already contacted law enforcement and they request that you detain the subject, Nevada Revised Statue 171.132 and 171.134, permits you to aid the arresting officer for ANY crime, even prior to the arrival of the LEO. So CYA keep the law on speed dial :)