CASPER, Wyo. — Three defendants have pleaded guilty to an alleged fentanyl delivery conspiracy involving three generations of a family that also ran a suicide prevention nonprofit in Natrona County for a decade.
Mari June Manthei-Robinson, 59, entered an Alford guilty plea to the charge of conspiracy to deliver fentanyl in Natrona County District Court on Wednesday. An Alford plea means that the defendant essentially maintains her innocence but does not wish to challenge the state’s evidence at a trial.
Manthei-Robinson is also a former deputy county coroner, and worked at the office until just before her arrest late last November. Two of her children, Bryson Manthei and Braunwyn Cheyenne Eaby, were also charged, along with Eaby’s boyfriend, 26-year-old Torrey Miller-Topping.
81-year-old Romona Manthei was also charged in the conspiracy, and pleaded guilty at her arraignment earlier this year. Eaby pleaded guilty on Tuesday. The three guilty pleas come only with the state’s assurance that it will ask for no more than five years in prison at future sentencing hearings.
Manthei-Robinson was also the founder and executive director of Drew’s Decision, a suicide prevention nonprofit established a decade ago in Mills. The nonprofit has been dissolved since the charges surfaced, according to state records filed in May.
The Wyoming Division of Criminal Investigations agent noted in the charging documents that substance addiction is often a component of mental health struggles. The agent considered Manthei-Robinson’s contact with the nonprofits’ clients — and her position as a deputy coroner — to be “aggravating factors” in the investigation.
Manthei-Robinson denied ever taking prescription drugs from any scene she attended in her capacity at the coroner’s office, according to the affidavit.
The agent stated in the affidavit that Manthei-Robinson had contacted DCI asking for the reports from a fatal overdose investigation last summer. The agent found this “very suspicious” and believed Manthei-Robinson knew that her children had distributed to another individual who was present during the overdose.
DCI agents reference two fatal overdoses last summer in their summary of the investigation.
The DCI investigation began in November 2021, when sources identified Bryson Manthei and Miller-Topping as distributors of fentanyl. Agents were granted search warrants for various cash transfer and messaging accounts that yielded exchanges that agents believe pertained to the purchase and distribution of fentanyl as well as the collection of drug-related debts.
Among the exchanges were discussions about the prices for “blues“ and “blue paint” — known by agents to reference fentanyl distributed in the form of blue counterfeit OxyContin pills.
In one exchange with Manthei, another alleged distributor referred to “the strongest presses I’ve ever had.”
In a text exchange with one buyer, Eaby reportedly said “everyone in town would end up being … sick” due to a feared inability to get re-supplied.
Based on interviews with the suspects, agents believe Miller-Topping, a former Colorado resident, traveled to Denver about three times per month, purchasing 500-1,000 fentanyl pills at a time. They believe he sold about 300–500 pills per week.
Manthei-Robinson, Miller-Topping and Eaby were arrested on Nov. 22, 2022, after DCI agents executed a search warrant on properties in Mills owned by Manthei-Robinson.
Investigators say they found 130 presumptive positive fentanyl tablets. About 2.3 grams of methamphetamine was also found in a backpack believed to be Miller-Topping’s, according to the affidavit. Agents say they found about 40 grams of suspected methamphetamine during a search of the couple’s east Casper apartment later that day.
Having pleaded not guilty late last year, Miller-Topping is scheduled for a change of plea this month. Bryson Manthei pleaded not guilty earlier this year, and is currently incarcerated after a bond revocation, according to court records.
Miller-Topping and Bryson Manthei are presumed innocent until proven or pleading guilty.
