The fifth and final defendant charged in the drug overdose death of a Woodbury girl last year was sentenced Thursday after his father delivered an emotional apology to the girl's parents.

Alistair Curtis Berg, who was 17 when fellow Woodbury High School junior Tara Fitzgerald died after taking a dangerous synthetic drug, pleaded guilty to third-degree controlled substance crime, a felony, while a third-degree murder charge was dismissed.

Berg will spend 11 weekends in a Ramsey County juvenile detention center. He also received a 21-month prison sentence that won't be imposed if he follows conditions of his probation.

Fitzgerald died on Jan. 11, 2014, after placing a paper tab on her tongue that she was told was LSD. Testing showed the drug was a hallucinogenic chemical known as 25i-NBOMe.

Berg bought three tabs of the drug from Sydney Claire Johnson, who was sentenced in January. He didn't consume any of the tabs, but sold them to Brian Phillip Norlander, and watched as Norlander sold the drug to Fitzgerald the day before her death.

"I can't express enough my sorrow," Guy Berg, Alistair's father, said to Tom and Mai Fitzgerald in the courtroom. "No parent should ever experience the loss of a child, ever."

Guy Berg then expressed his disappointment to his son, a high school senior.

"I hope you take the pain and guilt from this and make something constructive of your life," he said.

The younger Berg will spend 150 hours in community service, pay restitution, and participate in a face-to-face conference with Tara's parents should they choose to do that.

Before sentencing, Kathryn Berg asked Judge B. William Ekstrum not to send her son to jail.

"I'm a little concerned that there will be no protection for Alistair if he's put in a facility with people in there for more serious crimes," she said. "His needs are different from all the other people involved in this situation."

Ekstrum denied that request, saying Alistair Berg, now 18, must be held accountable for Tara's death.

"What you did was wrong, what you did caused untold grief," Ekstrum said. He did, however, give Berg credit for one weekend already spent in jail.

Tom Fitzgerald, talking outside the courtroom afterward, said he was relieved that the string of five sentencings was finished. At every one, he had read an impassioned statement describing his family's grief after losing Tara.

"It got harder each time," he said.

Kevin Giles • 651-925-5037