PORTLAND, Ore. -- An accused fentanyl trafficker pleaded guilty in federal court on Wednesday for selling fentanyl pills which caused the death of a Portland high school student back in March 2022.

Griffin Hoffmann, 16, was a varsity tennis team captain at McDaniel High School in Portland. Before school on a Monday morning that March, he took a single blue pill that he thought was oxycodone. Investigators later confirmed that he'd overdosed on fentanyl, one of many to succumb to the "M30" counterfeit pills.

"The first thing I saw was his hand, 'cause his dad was holding it trying to find a pulse, and there was no pulse and it was just blue," Kerry Cohen, Hoffmann's mother, told KGW a few months after his death. "My kid wasn't an addict, you know ... he was just doing normal experimentation like any other kid. He was just like a regular teenager."

In the weeks after Hoffmann's death, investigators traced the blue pills found in his bedroom up to 24-year-old Manuel Antonio Souza Espinoza, an alleged "third-level" drug trafficker living in Vancouver. Between Espinoza and Hoffmann, prosecutors claimed, the pills went through two lower-level dealers. Espinoza has been behind bars since his arrest on March 31, 2022.

Almost three years later, inside the federal courthouse in downtown Portland on Wednesday morning, Espinoza accepted a plea deal, changing his plea to guilty in exchange for the government not seeking a 20-year mandatory minimum sentence.

RELATED: Accused fentanyl dealer sued by family of Portland teen who died of overdose

The two federal charges Espinoza faces -- conspiracy to distribute and posses with intent to distribute fentanyl resulting in the death of a minor, as well as possession of a firearm in furtherance of a drug trafficking crime -- could have imprisoned him for life if he'd been handed the maximum sentence.

But after Espinoza's guilty plea, prosecutors recommended a sentence of 13 years in prison followed by supervised release.

Espinoza's large family, including young children, showed up for his plea hearing. Cohen did as well.

"It doesn't do anything for me," Cohen said of the conviction. "He obviously did a very bad, selfish, greedy thing, which is he sold poison under the guise of something else and didn't consider that that was not only going to kill people, but might have killed kids, which is what happened to my son."

"He had a lot of family there -- that was both surprising and, you know, nice," Cohen added. "I look forward to the sentencing because that means they'll all be there when I get to talk."

Espinoza did not finish high school and is not a U.S. citizen. The federal judge warned that Espinoza's guilty plea means it's "extremely likely" that he will be deported, and court documents say that outcome is "practically inevitable."

"I think he made really terrible choices," Cohen said of the man. "He didn't look my kid in the eyes and hand him the drugs -- if he had done that, maybe I'd feel differently. And maybe I'll feel differently about the person who did that, if and when we go after him."

In the meantime, Cohen tries to keep her son's memory alive by sharing a message for other parents, giving the context for her loss.

"There's a lot of misunderstanding around all of these horrendous fentanyl deaths that are happening all over the place, and it's a very layered, complicated situation," she said. "It was one pill, it was one little pill, and (Griffin) thought he was just going to feel good, go to sleep, wake up, go to school the next day. He had no idea he was going to die."