Where Do I Stand?

So after 2+ months in this job, I've come across some situations in which I've been having trouble being completely objective. It's true that for the purpose of this blog I'm an observer, but I never thought about possible interferences with the law. This job requires me to maintain a safe shopping environment for the customers, which means my moral stance needs to be on the side of the law should something happen. For instance, I've had multiple occurrences in which my moral fiber was tested. A month or so ago a customer dropped some marijuana on the counter by accident. At this time I was still new to the system so I decided to tell him to put it away immediately (because the cameras might or might not have picked it up) and let him leave. However, this question of legality would not be the last. And keep in mind, I don't want the cops in the store. Not because I'm doing anything illegal, I just don't want to deal with the process. So for the most part I will "let it slide." But today, I witnessed a situation that left me wondering if I did the right thing. Three -let's call them "rugged" types- entered the store and bought their chips and sodas while discussing Hemp fest. The third guy to come up to the register pulled out a vile and offered his friends something. Assuming that the contents of the vile were as substance more criminally offensive than marijuana, I told them to get out. I know the camera picked it up but I'm not sure if my managers will check the footage. I also didn't want to get them in trouble for a non-harmful crime that didn't directly affect the well-being of the store. So once again, I "let it slide." I'm not sure if I did the right thing legally but I know I did the right thing personally. Please comment if you feel I did the right thing or not, and as always, have a nice day.