Skip to main content
Press Release

Porcupine Man Indicted for Involuntary Manslaughter

For Immediate Release
U.S. Attorney's Office, District of South Dakota

RAPID CITY - United States Attorney Alison J. Ramsdell announced that a federal grand jury has indicted a Porcupine, South Dakota, man for Involuntary Manslaughter and Assault Resulting in Serious Bodily Injury.

Robert Cottier, age 64, was indicted in May of 2023. He appeared before U.S. Magistrate Judge Daneta L. Wollmann on May 26, 2023, and pleaded not guilty to the Indictment.

The maximum penalty upon conviction is 10 years in custody and/or a $250,000 fine, and three years of supervised release for each assault count, and eight years in custody and/or a $250,000 fine, and three years of supervised release for involuntary manslaughter. Also $100 to the Federal Crime Victims Fund for each count and restitution may be ordered.

The Indictment alleges that on February 18, 2023, near Porcupine, Cottier killed a man by operating a motor vehicle in a grossly negligent manner. Cottier is also alleged to have assaulted four other individuals, three of which were minors.

The charge is merely an accusation and Cottier is presumed innocent until and unless proven guilty.

The investigation is being conducted by the FBI and the Oglala Sioux Tribe Department of Public Safety. Assistant U.S. Attorney Anna Lindrooth is prosecuting the case. 

Cottier was released on conditions pending trial. A trial date has been set for August 1, 2023.

Updated June 6, 2023

Violent Crime
Indian Country Law and Justice