Keshena Man Sentenced for Fatal Drug Delivery in Tribal Detention Facility

Richard G. Frohling, Acting United States Attorney for the Eastern District of Wisconsin, announced that on May 16, 2025, Senior United States District Judge William C. Griesbach sentenced Warren Grignon (age 43) of Keshena, Wisconsin, to 12 years in federal prison for distributing fentanyl he smuggled into the Menominee Tribal Jail, which led to three overdoses, one of which was fatal. Those actions led to the February 7, 2025, entry of guilty pleas to charges of involuntary manslaughter and distribution of controlled substances. Grignon was sentenced to 12 years in prison for the distribution of controlled substances count and a concurrent 8 years in prison for the involuntary manslaughter count.

According to court records, Grignon was booked into the tribal jail on December 22, 2023, and moved into a cell with other inmates on December 23, 2023. Grignon distributed a substance containing fentanyl to three other inmates, who ingested the drug that afternoon. All three inmates overdosed, and responding jail personnel, tribal police, and EMTs managed to revive two of the inmates. Tragically, one of the inmates died.

At the sentencing hearing, Judge Griesbach noted that the serious nature of the offense and the profound effect Grignon’s actions had on the community required a lengthy prison term. Following his 12-year prison sentence, Grignon will be on supervised release for an additional 10 years. He was also ordered to pay $6,943 in restitution to the victim’s family.

The Menominee Tribal Police and Federal Bureau of Investigation investigated the case. It was prosecuted by Assistant United States Attorney Andrew J. Maier in the United States District Court in Green Bay.

NOTE: This press release was submitted to Urban Milwaukee and was not written by an Urban Milwaukee writer. While it is believed to be reliable, Urban Milwaukee does not guarantee its accuracy or completeness.