FARGO, N.D. — A former University of North Dakota student who pleaded guilty to financing a man who manufactured the synthetic drugs that resulted in the deaths of two teenagers in the Grand Forks area was sentenced Monday to 20 years in prison.

Casey Rosen, of Minneapolis, pleaded guilty in January 2013 to conspiracy to possess with intent to distribute controlled substances resulting in serious bodily injury and death. The charge carries a maximum sentence of life in prison.

Assistant U.S. Attorney Chris Myers said Rosen, 24, was a partner with Andrew Spofford, who pleaded guilty earlier to cooking up chemicals he ordered online. Rosen, Myers said in court Monday, was “essentially the money man financing the operation, for one sole purpose, to make money.”

Spofford, who was sentenced last month to 17 1/2 years in prison, said in a letter to U.S. District Judge Ralph Erickson that it would be unfair for Rosen to receive more prison time than him.

But Judge Erickson noted that Rosen, unlike Spofford, had a prior felony conviction.

Robert Paule, Rosen’s attorney, argued for a sentence of 15 years for Rosen, who has a history of depression and a chronic sleep disorder. Paule acknowledged it was a serious crime and said he “wasn’t here to make excuses” for Rosen’s conduct.

Rosen is one of 15 people charged and the 13th person sentenced in the case federal authorities have dubbed “Operation Stolen Youth.” The investigation began when Christian Bjerk, 18, of Grand Forks, and Elijah Stai, 17, of Park Rapids, died within a week of each other in June 2012 after ingesting the drugs.

Erickson said it’s a “remarkably sad case” that is unique because most of the defendants come from “good families by and large” and are not connected to drug cartels. He said the conspiracy involved “a bunch of college kids” who fancied themselves as amateur chemists but didn’t know what they were doing.

“You know what? You sell drugs, people are going to die,” the judge said.

Erickson ordered Rosen to pay back $100,000 in alleged drug profits.

Authorities said Spofford bought the chemicals from Motion Resources LLC, a Houston company that imported controlled substances from Asia and Europe and resold them over the Internet to domestic buyers. Company owner Charles Carlton is scheduled to be sentenced next month. Sentencing for his assistant, John Polinksi, is set for June.