I am starting a career that can not be messed up with drugs or things of that sort. If I call the cops on my roommate could I be in trouble? Even if not convicted, me being arrested for the possibility would not be okay for my career.
I think I would move out before reporting your roommate, unless you are certain that the report will result in your roommate's removal. Other than pissing off the roommate, you should not have any trouble. Otherwise, if you are in a field where urinalysis is a concern, then continuing to coexist with a marijuana user, whose secondhand smoke you inhale, will be a very real problem for you at some point. And if your roommate gets caught, people will naturally look suspiciously at you. Good luck.
If you call the police, I doubt in this situation they would attempt to prosecute you if the decision was made to arrest your roommate, but you have other considerations. Understand that if your roommate was arrested over this, he/she would bond out of jail, and then you would have to live with this person while the case was pending. Your name may be listed in the arrest report in the case. How would your roommate react when this is discovered? Uncomfortable at best, potentially dangerous at worst. Move out.
I join my fellow contributors in the advice given. Find a place of your own - as has already been explained - calling the police is only going complicate this situation and not resolve it.
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