According to campus police, two students - Thomas Ricardo Cunningham, 21, and Mary Elizabeth Essa, 19 - baked THC-laced brownies for the class as part of a "bring food day."
The pair will appear in Boulder County court Monday morning.
Eight people who ate the brownies got sick and 3 were hospitalized.
"[Cunningham] definitely was not, had no intent of hurting anybody," said longtime friend and roommate Brooks Rice.
Rice grew up with Cunningham in Fort Worth, Texas.
Essa is from Las Vegas, Nevada.
"Don't judge [them]," said Rice "Mistakes happen, some bigger than others."
"They had baked those brownies, and put THC or some type of marijuana substance into the brownies," said Ryan Huff, spokesperson for University of Colorado Boulder Police Department.
The professor and classmates were unaware that the brownies contained THC (tetrahydrocannabinol), the active ingredient in marijuana.
UCPD responded to the Hellems Arts and Sciences Building Friday on a report of a professor who was complaining of dizziness and going in and out of consciousness.
"One can only imagine had she been in the car, had she been with her children in the car, when the drugs started to take effect, what could have been the outcome of this, and it's just a terrible, irresponsible and reckless act," said professor Susan Kent, who chairs CU-Boulder's history department and spoke on behalf of her colleague.
Paramedics transported the female professor to the hospital.
Later that afternoon, a student's mother notified campus police that her daughter, who attended the aforementioned professor's class, was at a local hospital having an anxiety attack.
On Saturday, police got another report that a second student felt like she was going to "blackout" after the class. Her family took her to the hospital for evaluation.
An investigation revealed that the three hospitalized victims and five other classmates were suffering from the effects of THC.
"This was just a stupid, irresponsible act," said Bronson Hilliard, CU's spokesperson.
He and Huff, with UCPD, say the incident had nothing to do with Amendment 64 and the looming legalization of small amounts of marijuana.
"Putting marijuana in a food product and providing it somebody without their knowledge has always been illegal, and that will continue to be illegal, even after Amendment 64," Huff said.
9NEWS legal analyst Scott Robinson says, on paper, the charges could add up to decades in prison, but he says that likely won't happen.
"A prank can quickly turn into a felony charge and a felony conviction record. If there was no truly evil intent, the likelihood is that these young people will get probation," Robinson said.
Possessing and using small amounts of marijuana will soon be legal in Colorado for adults 21 and older.
But under Colorado law, drugging someone without their consent is a serious crime.
Each count could mean up to 12 years in prison, and remember 8 people were allegedly drugged in this case.
The students, Essa and Cunningham, are each facing four felony charges related to the incident, including second degree assault and inducing consumption of a controlled substance by fraudulent means.
The two are being held in Boulder County Jail without bond. A spokesperson for CU says if Essa and Cunningham are found guilty through an internal University process, they could face suspension or expulsion.
Three other hospitalized victims have been released.
UCPD believes this is an isolated incident and there's no ongoing threat to the campus community.
Rice worries how these charges will affect his roommate's future. "It could have an effect on his whole life. That's the worst," he said.
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