SPRINGFIELD — While people stood in line Tuesday to purchase recreational marijuana from a dispensary, several blocks away the Illinois Supreme Court heard oral arguments in a criminal case addressing a state law that lessened the penalty for cannabis possession.

People v. Charles D. Hill was one of four criminal cases before the high court on Tuesday. The court heard arguments in two civil cases Wednesday.

In the Hill case, the justices appeared divided on the question of whether the Illinois Cannabis Control Act, which in 2016 reduced the penalty for possessing less than 10 grams of cannabis from a “criminal act” to a “civil law violation,” changed the basis for probable cause in a warrantless search of Charles Hill’s car.

In June 2017, a Macon County police officer searched Hill’s vehicle during a traffic stop, prompted by the “odor of raw cannabis” and a “bud in the backseat.” The search uncovered cannabis residue and a rock of crack cocaine.

Hill was charged with possessing less than 15 grams of cocaine — but not cannabis possession, which would have been a civil violation under the law at that time.

In October 2017, Hill filed a motion in the Decatur courthouse to suppress the evidence.

Sixth Judicial Circuit Judge Thomas E. Griffith Jr. granted the motion, ruling the search would have been justified if the stop was valid.

In January 2019, a 4th District Appellate Court panel reversed Griffith’s ruling, finding the stop was justified and the odor of cannabis provided probable cause to search Hill’s car.

Hill appealed to the Illinois Supreme Court, which accepted his petition.

Three high court justices handled the majority of the questioning. Justices P. Scott Neville Jr. and Thomas L. Kilbride remained silent during the arguments.

Justice Robert R. Thomas asked Assistant Appellate Defender Zachary A. Rosen if “‘decriminalization’ is synonymous with ‘legalization.’”

Rosen responded that although they are not the same, the statutes for the legalization of medical marijuana and the decriminalization of small amounts of cannabis are largely similar because “there’s an allusion in the laws that says cannabis should no longer be considered as always contraband.”

That “allusion” relates to language in the law about “forfeiture.”

The Compassionate Use of Medical Cannabis Program Act says only medical cannabis “may not be seized or forfeited.” The Illinois Cannabis Control Act says that only “contraband,” or more than 10 grams of cannabis, is “subject to forfeiture.”

Rosen argued that if a police officer took pot from someone with a medical marijuana card, it could be returned, and they have a possessory interest in the cannabis. This implies that cannabis isn’t always contraband, according to Rosen.

But the officer that searched Hill’s car wasn’t thinking that, Rosen said.

“The officer still thought cannabis was contraband,” Rosen said. “Unless in the plain view of the officer it’s clear … that there was more than 10 grams there, the officer had no reasonable belief, not even anything to suggest that Mr. Hill or his passenger possessed a criminal amount of cannabis.”

Chief Justice Anne M. Burke did not appear convinced.

“It would be kind of foolish to think that, to require the police officer to know how much was there before it could show probable cause, isn’t that right?” Burke asked.

Rosen agreed, but contended that because an officer may not know how much cannabis is present in a vehicle by smelling or seeing it, other factors should be considered before the officer determines whether there is probable cause to search the car.

That argument wasn’t enough to move two of the court’s justices past Rosen’s earlier claims that “contraband” could not justify probable cause under the laws in place at the time of the search.

Justices Lloyd A. Karmeier and Thomas posed that logic directly to Assistant Attorney General Garson S. Fischer.

In response, Fischer said the high court’s 1985 decision in People v. Stout, which held the odor of cannabis justifies probable cause in warrantless searches, applies to Hill’s appeal.

Justice Mary Jane Theis asked who has the burden of proof regarding legal possession of marijuana — the passengers or the officer.

“The fact that a very small number of people under very specific circumstances in 2017 could obtain a license to possess marijuana doesn’t change the fact that the odor of marijuana provided very high probability to believe that it was contraband and illegally possessed,” Fischer said, echoing the Stout decision.

Karmeier advised the court to take care in crafting its opinion not to “prejudge what might happen” in a post-legalization world.

However, Fischer said, “If the question of probable cause comes to the court in a post-legalization time, then the court will have to deal with it then.”

This case is People v. Charles D. Hill, No. 124595.