If they are thinking about charging you with a misdemeanor, the DA and the cops have 18 months to file charges. If they are anticipating charging you with a felony theft, they have 3 years to file charges. As such, they have plenty of time to file charges. The mere fact that you were detained on location and then arrested and released almost immediately does not change the statute of limitations for filing charges.
The information provided in this answer does not create an attorney-client relationship. If you are interested in his legal services, feel free to call Chris at (303) 409-7635 at his law office in the Denver Tech Center. All initial consultations are free of charge.
Chris is correct on the statute of limitations. I would add that if you are charged, thus having more law enforcement contact, exercise your right to remain silent and right to an attorney. Only provide the police with name, address, dob, ss#, and be polite. Chris Leroi is a highly recommended attorney in your area.
Marijuana is against federal law. Federal law supersedes state law. A person could be charged and convicted for marijuana related crimes such as possession, cultivation, distribution, manufacturing, transportation, and conspiracy.