Wasilla man pleads guilty to distributing carfentanil resulting in the death of a 16-year-old girl

Sean Mobley, 45, from Wasilla, pleaded guilty last week to federal charges including distributing carfentanil to two people, resulting in the fatal overdose of a minor victim and the near fatal overdose of an adult victim. He also pleaded guilty today to a felon in possession of firearms charge filed through a separate federal indictment in July.

In a press release from the Department of Justice, United States Attorney’s Office District of Alaska, in November of last year, Mobley agreed to supply an individual with .25 grams of fentanyl powder to distribute to another person. Mobley gave the individual a powdered substance that he believed was fentanyl but was, in fact, carfentanil. Carfentanil is an opioid used by veterinarians and is 100 times more potent than fentanyl.

Mobley and the individual drove to a residence in Wasilla, at which point the individual entered the residence and sold the substance to an adult victim for $100. The individual returned to the vehicle and gave Mobley the money from the sale. Shortly after the purchase, the adult victim used the substance and overdosed, causing serious bodily injury.

After distributing the substance to the adult victim, Mobley then drove to a local gas station where he dropped the individual off and picked up a 16-year-old victim, later identified as Alena Toennis. Mobley took the Toennis to an isolated location intending to use drugs together. He then gave some of the substance he believed was fentanyl powder to her, and upon using the substance, and Toennis immediately overdosed and lost consciousness. Believing her to be dead, Mobley dumped her body in a remote area and fled.

On January 28, 2025, Mobley possessed a shotgun inside a vehicle he was operating. He already had three prior felony convictions from 2002 and 2003, making him a felon in possession of a firearm.

On June 10, a federal grand jury returned an indictment charging Mobley with distribution resulting in death and serious bodily injury. On July 17, a federal grand jury returned a separate indictment charging Mobley with being a felon in possession of a firearm and being an unlawful drug user and addict in possession of a firearm.

“It’s hard to explain it wasn’t relief or happiness, it brought up a lot of emotions,” says Elyssa Toennis, sister to Alena, about the guilty plea and the aftermath of their loss and subsequent case working through the state and federal systems. “It felt like a wave of sadness, hurt, and anger coming to terms with it isn’t going to be easy. It was very hard to hear but, I’m grateful for everything to be moving forward.”

“I know he’s gonna serve time for what he did to her, and have to sit in a cell and think about her every day,” said Judy Eyre-Breuer, Toennis’ grandmother, during his arraignment in Palmer back in May.

Samantha Light expressed relief to the plea and disappointment that his charges were not more serious on the federal level. Mobley still faces multiple charges in Palmer in connection with the death of the 16-year-old, including murder and manslaughter for providing the fentanyl that led to her death.

Mobley is scheduled to be sentenced on January 22, 2026 and faces a mandatory minimum penalty of 20 years in prison but up to life in prison for the distribution resulting in death and serious bodily injury charge, and up to 15 years in prison for the felon in possession of a firearm charge. A federal district court judge will determine any sentence after considering the U.S. Sentencing Guidelines and other statutory factors.

U.S. Attorney Michael J. Heyman of the District of Alaska, Special Agent in Charge David F. Reames of the DEA Seattle Field Division and Alaska State Trooper Colonel Maurice Hughes made the announcement.

The DEA Anchorage District Office and the Alaska State Troopers investigated the case.

Assistant U.S. Attorneys Tom Bradley and Alana Weber are prosecuting the case, with assistance and collaboration from the State of Alaska Department of Law, Office of Special Prosecutions.