On May 16, 2025, Senior United States District Judge William C. Griesbach sentenced Warren Grignon, a 43-year-old man from Keshena, Wisconsin, to 12 years in federal prison. The sentence was for distributing fentanyl inside the Menominee Tribal Jail, which resulted in three overdoses and one fatality. These events led to Grignon's guilty pleas on February 7, 2025, to charges of involuntary manslaughter and distribution of controlled substances.
Court records reveal that Grignon was incarcerated at the tribal jail on December 22, 2023. He was placed with other inmates the following day and distributed fentanyl to three inmates who overdosed after ingesting the drug. Emergency responders managed to revive two of them, but one inmate did not survive.
Judge Griesbach emphasized the severity of the crime and its impact on the community as reasons for imposing a lengthy prison term. After serving his sentence, Grignon will be under supervised release for an additional ten years and must pay $6,943 in restitution to the victim's family.
The investigation was conducted by the Menominee Tribal Police and Federal Bureau of Investigation. Assistant United States Attorney Andrew J. Maier prosecuted the case in Green Bay's United States District Court.
