HARRISBURG - The smell of marijuana can be a factor police use to justify a search without a warrant but can’t be the sole basis for it, the Pennsylvania Supreme Court ruled Wednesday.

The court said a state police search of a vehicle in Allentown three years ago was conducted only because the troopers smelled marijuana.

“The odor of marijuana alone does not amount to probable cause to conduct a warrantless search of the vehicle but, rather, may be considered as a factor in examining the totality of the circumstances,” wrote Chief Justice Max Baer for the majority.

Troopers pulled over the vehicle after it had failed to stop at a solid white line before an overpass, and smelled burned marijuana through a window, Baer recounted.

Police found a plastic bag with less than 1 gram of marijuana next to the front center console, with no markings that would have indicated it was purchased from a dispensary. They also recovered a loaded handgun from beneath the driver’s seat.

The defendant, Timothy Oliver Barr II, and the driver, his wife, produced medical marijuana cards.

The trial court ruled the search unconstitutional and said the evidence it produced was not able to be used in court, and dismissed the charge of possession of a small amount of marijuana.

The Lehigh County district attorney’s office had argued that the drug remains illegal for most in the state even though medical marijuana cardholders can legally possess it. In a brief, prosecutors argued the odor of marijuana “has not lost its ‘incriminating’ smell by virtue of its legality for some,” because it’s illegal for most.

The Supreme Court majority said there was sufficient grounds to support the trial judge’s determination that the troopers searched the vehicle based solely on the smell. The majority reinstated the order suppressing the evidence.

In a separate opinion, Justice Kevin Dougherty noted the marijuana recovered in the search was not in packaging provided by a licensed dispensary.

“Where an officer who smells marijuana also observes its packaging (or lack thereof) and there is no barcode or other identifying information that typically appears on the original packaging from a dispensary, that could be enough to establish probable cause,” Dougherty wrote.