In Georgia, existing court precedent is that the odor of marijuana emanating from a vehicle provides police with probable cause to search that vehicle.  In Gowen v. State, the Georgia Court of Appeals faced one of its early challenges to that doctrine based on the enactment of the Georgia Hemp Farming Act, which went into effect on May 20, 2019.

Gowen was stopped based on a license plate check which showed an outstanding federal warrant for a drug offense.  Officers made contact with Gowen after he exited his vehicle near a trailhead.  Upon being detained, Gowen wanted his cell phone to call his sister, an attorney.  He gave his vehicle keys to one of the officers for the limited purpose of entering the vehicle to get his mobile phone.  Upon opening the vehicle, the officer reported smelling an odor consistent with "marijuana."  That odor and the existence of the federal warrant was claimed as probable cause to search the vehicle.  The subsequent search found a small amount of cocaine and a small amount of loose "marijuana shakes," loose leaf material.  The "marijuana" was not tested or prosecuted.  Gowen was prosecuted for possession of cocaine.

Cannabis sativa is the plant that produces what we know as marijuana and hemp.  The difference between marijuana and hemp is THC concentration.  Hemp has less than 0.3% THC.  Marijuana has significantly more THC concentration.  THC is itself odorless.  There is no difference in appearance or odor between marijuana and hemp.

So, when an officer reports smelling raw, burning or burnt "marijuana," a more accurate statement is that they are smelling raw, burning or burned cannabis.

Prior to May 20, 2019, the distinction did not matter because both marijuana and hemp were illegal and were treated the same under Georgia law.

It is axiomatic that if an odor of an illegal substance is identical to that of a legal substance, then that common odor could not justify a Fourth Amendment intrusion.  

The Clarke County Superior Court upheld the search based on the precedent first described above, despite testimony and argument that should have raised questions about the continued viability of the doctrine.

So, how did the Georgia Court of Appeals avoid confronting the real issue in the case?

First, they did acknowledge that some hemp products are now legal under the Georgia hemp farming act.  However, the hemp must be processed before entering the retail sphere.  While processing is not described specifically in the act, it is specifically noted that processing requires more than "merely placing raw or dried material into another container or packaging raw or dried material for resale."  OCGA 2-23-3(1)(B)(i).  The Act also does not allow a person to offer for sale at retail the unprocessed flower or leaves of the hemp plant.  OCGA 2-23-4.  Based on that last statute, the Court of Appeals made a logical leap to opine that the act does not allow for the possession of raw hemp by anyone other than a license or permit holder under the Georgia Hemp Farming Act.

The court then engages in a bit of willful blindness, although it could be argued that the trial court record was deficient on this point, that there is no processed hemp product that is designed to be burned or smoked.  A quick internet search would have pointed them to plenty of Georgia retailers offering pre-rolled hemp/CBD cigarettes as well as other hemp products designed to be burned.  Interestingly, there also appear to be plenty of processed hemp flowers for sale.  The court then uses the supposed absence of a hemp product that would be burned to justify the continuation of its precedent that the odor of cannabis, raw, burned or burning, is sufficient to give an officer probable cause to search a vehicle.

In a concurring opinion, Chief Judge McFadden takes the argument much further.  It is his position that even if hemp and marijuana do smell the same, an officer's mistaken belief that it is marijuana and not hemp will still justify a search of the vehicle.  So, for him, even the odor of a legal substance would justify a Fourth Amendment intrusion.  This logical construction is based on his fallacious premise that an officer could reasonably believe the odor was marijuana notwithstanding the scientific certainty that there is no way for humans or canines to distinguish by smell between hemp and marijuana.  So long as the officers avoid any training that includes such scientific facts, they could continue to assert that they reasonably thought it was marijuana not hemp.  The officer in this case had extensive training in drug recognition and related subjects, but, strangely, none of his training include anything about the odor or characteristics of hemp versus marijuana.  The concurring opinion will give law enforcement motivation to continue to omit such facts from their training in order to more regularly intrude into areas where the Fourth Amendment should prevent them from being.

Hopefully, future challenges to the doctrine will include the evidence to close the gaps in the appellate courts' knowledge about Cannabis sativa (hemp and marijuana).