A teenager implicated in the drug overdose death of a Woodbury girl pleaded guilty Friday to an adult felony charge of conspiring to sell and deliver a controlled substance to someone under 18.

Sydney Claire Johnson, who was 17 when she bought and sold the synthetic hallucinogenic drug that killed fellow Woodbury High School student Tara Fitzgerald, received a 57-month prison sentence that won't be imposed as long as she obeys the law until she is 21.

The drug was marketed as LSD but instead was a synthetic substance known as 25i-NBOMe.

Investigators say the drug, manufactured on small bits of colored paper and wrapped in tinfoil, contains dangerous chemicals.

"Synthetic drugs are a significant public safety danger to our community," Washington County Attorney Pete Orput said Friday. "Too many young people are purchasing, selling, and ingesting these dangerous drugs without understanding the severe consequences of doing so."

Johnson also will serve 18 weekends in jail, perform 200 hours of community service, pay $23,845 in restitution and remain on probation until she is 21.

She also would be required to face Fitzgerald's parents, Tom and Mai Hoang Fitzgerald, should they decide they want moderated sessions to talk with her about their grief.

Judge John Hoffman told Johnson she must use her community service to inform other people of the hazards of drug dealing and how it hurts families.

In Washington County District Court, Johnson asked Fitzgerald's parents for forgiveness.

"I'll think about Tara every day for the rest of my life," she said.

Fitzgerald was 17 when she died on Jan. 11, 2014, after taking a poisoned dose of the drug.

Murder charge dismissed

The sentencing agreement included dismissal of a more serious third-degree murder charge against Johnson because she helped prosecutors with investigations of four other defendants, said Tony Zdroik, the juvenile division chief in Orput's office.

"Her plea still holds her accountable for a very serious offense," Zdroik said.

Two adults who were 19 when charged last May have been convicted and sentenced in the case. Alexander Lee Claussen, of St. Cloud, was sent to prison in January. Cole Alexander Matenaer, of Woodbury, will serve a year in jail.

Court hearings for the final defendants, Alistair Curtis Berg and Brian Phillip Norlander, will be held within the next month. Both are from Woodbury and were 17 when they were charged last year.

Fitzgerald's father, in a statement to the court Friday, decried "drug dealers" who prey on high school students and said the defendants killed his daughter.

"If you are responsible for Tara's death, own it, because you owe it," Tom Fitzgerald said.

Kevin Giles • 651-925-5037