Source: Office of United States Attorneys
Gregory J. Haanstad, United States Attorney for the Eastern District of Wisconsin, announced that on February 7, 2025, Senior United States District Judge William C. Griesbach accepted the guilty pleas of Warren J. Grignon to one count of distribution of fentanyl in violation of 21 U.S.C. § 841 and one count of involuntary manslaughter in violation of 18 U.S.C. §§ 1111 and 1153(a).
According to the indictment and plea agreement, Grignon was an inmate at the Menominee Tribal Detention Center in Keshena on the Menominee Indian Reservation. On December 23, 2024, Grignon distributed fentanyl he smuggled into the jail to three other inmates. All three inmates overdosed. Two inmates were revived through the efforts of additional inmates, corrections staff, and responding officers from the Menominee Tribal Police Department. One inmate could not be revived and was pronounced dead. A later autopsy revealed the cause of death to be a fentanyl overdose.
The sentencing hearing is scheduled for May 16, 2025, at 10:30 a.m., before Judge Griesbach. Grignon faces a total sentence of up to 28 years in prison as well as fines and assessments for each count. Grignon also faces a minimum term of three years, and up to a lifetime of supervised release after completing any period of imprisonment.
The Menominee Tribal Police Department and FBI investigated the case, with valuable assistance from the Department of Pathology and Laboratory Medicine at the University of Wisconsin School of Medicine and Public Health. Assistant United States Attorney Andrew J. Maier is prosecuting the case in the United States District Court in Green Bay.
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For further information contact:
Public Information Officer
Kenneth.Gales@usdoj.gov
(414) 297-1700
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