Are police not allowed to search a car just because they smell pot? No, that's missing important context: As of November 2021, an Illinois judge ruled the smell of marijuana does not give probable cause for officers to search a car. However, marijuana is still illegal in the majority of states, and police can still search cars in these states if they say they smell marijuana -- and people can still be arrested for possession of the drug.
The claim appeared in a Facebook post (archived here) on December 14, 2021. It opened:
New law just passed 🤞🏾 police CAN NOT search yo car off just ⛽️ smell gotta be other reasons too & anything under 35g's they can't fwy for it either spread da word and kno y'all car rights!
This is what the post looked like on Facebook at the time of writing:
(Source: Facebook screenshot taken on Mon Dec 20 21:55:32 2021 UTC)
The person who posted the message claims South Chicago, Illinois, as their original home state, and his post could well be a reference to that recent legal decision. While the post does not mention marijuana or any other substance, it's a safe assumption that the implication is there.
The claim in the Facebook post is only true in a small handful of states.
According to a Washington Post article in June 2021 titled, "A whiff of pot alone no longer airtight probable cause for police to search cars in several states," few states have ruled that the smell of marijuana is not enough for a search. The post is very broad in its statement about probable cause and law enforcement but there are other factors that can lead to police suspicion, such as the smell of alcohol on the driver.
New York passed a law in March 2021 that the smell of marijuana is no longer probable cause for officers to search a car, archived here. After the law passed, the New York Police Department released a memo to officers in April 2021, the New York Daily News reported:
Effective immediately, the smell of marijuana alone no longer establishes probable cause of a crime to search a vehicle. This change applies to both burnt and unburnt marijuana.
Other states where marijuana has become legal are in the process of not allowing police to use the smell of marijuana as justification for searching cars, such as Colorado as the Denver Post reported, but that is not happening across the country.
While the Facebook message is correct for the states of Illinois and New York as of December 17, 2021, it does not make it clear that this is not the law uniformly across the country. Since marijuana is still illegal in 31 states, police can still search a car if they claim they smell pot in most jurisdictions.
Here are the 19 states plus Washington, D.C. and Guam where recreational marijuana is legal compiled in October 2021 by U.S. News & World Report:
Colorado
Washington
Alaska
Oregon
California
Maine
Massachusetts
Nevada
Michigan
Vermont
Illinois
Arizona
Montana
New Jersey
South Dakota (a legalization measure was approved but is pending a lawsuit)
New York
Virginia
New Mexico
Connecticut