Chicago criminal defense attorney Robert J Callahan has defended marijuana charges for over 20 years.Basically, the law on the smell of weed (or any drug) & probable case is:“This court has held that distinctive odors can be persuasive evidence of probable cause. A police officer's detection of controlled substances by their smell has been held to be a permissible method of establishing probable cause. This method of detection does not constitute an unconstitutional search.”Practically speaking this means: if the drugs smell up your car, that’s probable cause.However, given the decriminalization of marijuana in Illinois and the ever changing state of cannabis laws, a fair question arises:If under 10 grams of marijuana is not a crime in Illinois: Is the smell of marijuana probable cause of a crime?Smell won’t tell you the quantity of something, only possibly its presence. You could be smelling a decriminalized amount or something more. So is the smell of marijuana still a reliable indicator that crime actually afoot? Clear enough that the police should be able to search you and your whole car?Enter the 1st Judicial District (Cook County) of Illinois to the rescue, or to ruin your high.In In re O.S., O.S., a juvenile, was armed with a handgun, parked in a no parking zone, smoking blunts. Chicago Police passed by the car and noticed a strong odor of marijuana. They then blocked in the car, approached it, and eventually searched the O.S. and the Lexus. O.S. argued that the smell of marijuana no longer justified a search and seizure under the 4th amendment given the new developments in cannabis law in Illinois and nationwide.Specifically, O.S. pointed to a recent case from the Massachusetts Supreme Court that questioned the concept of probable cause/reasonable suspicion based on the smell of marijuana.In Commonwealth v. Cruz, the Massachusetts Supreme Court held that the mere odor of marijuana no longer provides officers reasonable suspicion of criminal activity. Their logic was as follows:the voters intended to treat offenders who possess one ounce or less of marijuana differently from perpetrators of drug crimes & changed the status of possessing one ounce or less of marijuana from a crime to a civil violation,”Therefore, the “odor of burnt marijuana alone cannot reasonably provide suspicion of criminal activity.Additionally, a recent case out of New York held that that mere odor of cannabis, “without more,” is no longer enough to justify a stop of a pedestrian. However, most courts in States with recreational and medical marijuana reached the opposite conclusion.Colorado: “a substantial number of other marijuana-related activities remain unlawful,” and thus “the odor of marijuana is still suggestive of criminal activity.” California: “the fact that defendant had a medical marijuana prescription, and could lawfully possess an amount of marijuana greater than that . . . initially found, does not detract from the officer's probable cause.” Maryland: decriminalization “does not alter” existing case law justifying a search based on the smell of marijuana. Vermont: Medical marijuana, “does not undermine the significance of the smell of marijuana as an indicator of criminal activity.” Arizona: Despite enacting medical marijuana, “the odor of marijuana in most circumstances will warrant a reasonable person believing there is a fair probability that contraband or evidence of a crime is present.”But If it’s legal or a I can’t get arrested, then: Why Is It Probable Cause?Illinois (In re O.S.): “Because decriminalization is not synonymous with legalization, even though possession of less than 10 grams of cannabis is no longer a crime in Illinois, it remains illegal.”This logic keeps alive the rule in Illinois that the smell of marijuana provides probable cause to search your vehicle during a traffic stop. Essentially, while the smell of cannabis could simply mean the presence of less than 10 grams, (fine only), it could also indicate pounds, (illegal).Whether or not marijuana is legal, you should not smoke it in your car. Safety issues and DUI concerns aside, the best legal advice for anyone who smokes marijuana is: DON’T SMOKE WEED IN YOUR CAR.No matter if marijuana is legal, illegal, or decriminalized. If you follow this advice, the chances of getting arrested for smoking marijuana are slim.So pick it up from your boy, drive home, close your door, put on the Netflix, and enjoy your marijuana in the comfort of your own home. No cops are going to interrupt your session. Who cares about probable cause at that point, this bigger questions is: when is the pizza ready?For more information call the top criminal defense attorney in Chicago Robert J Callahan.With the passage of Public Act 99-697, § 40, as of July 29, 2016, Illinoisans are free to run around with 10 grams or less of marijuana without having to worry about Johnny lawdog. Across the country, more and more States are going beyond decriminalization and straight up legalizing marijuana, not to mention all the States that have medical marijuana. So the question arises, if weed is legal, or at least “decriminalized,” does the smell of the marijuana still constitute probable cause?Legalization and decriminalization of marijuana aside, Illinois law clearly states that the smell of marijuana alone is not enough for police to enter your residence without a warrant. On the other hand, it is firmly established that the smell of raw and/or burnt cannabis during a traffic stop provides probable cause to search you, your passengers, your vehicle and all its compartments, including your trunk. This has been the law in Illinois for over 30 years.