If police say they smell marijuana coming from your vehicle, you’re in a tough situation. Courts have ruled that the odor of contraband gives officers probable cause to perform a search. For this reason, police are quick to claim that they smell something and sometimes they might even lie about it.
All you can really do is say, “Officer, I have nothing to hide, but I don’t consent to any searches.” If they search you anyway and something is found, you’ll need an attorney to help you fight the charges. Unfortunately, police sometimes use tricks like this to circumvent your constitutional rights and there’s no perfect way to handle the situation. Of course, they are most likely to do this if they are suspicious of you for some reason, so do your best to stay calm.