Fort Thompson Woman Sentenced for Involuntary Manslaughter

U.S. Attorney’s Office, District of South Dakota
January 9, 2013

U.S. Attorney Brendan V. Johnson announced that a Fort Thompson, South Dakota woman convicted of involuntary manslaughter was sentenced on January 7, 2013, by U.S. District Judge Roberto A. Lange. Leigha Koster, age 20, was sentenced to 33 months of imprisonment, two years of supervised release, $100 to the Victim Assistance Fund, and $16,995.18 in restitution.

Koster was indicted for involuntary manslaughter and child abuse by a federal grand jury on August 14, 2012. The charges stem from an incident on July 28, 2012, when Koster was driving while under the influence of alcohol with her boyfriend in the passenger seat. Koster was stopped for a traffic stop. While the officer was reviewing the license plate on the vehicle, Koster took off. A high speed chase, in excess of 100 miles per hour, ensued. While attempting to make a turn, she lost control of the vehicle, causing it to roll and crash. Her boyfriend was ejected and died at the scene.

The investigation was conducted by the Federal Bureau of Investigation and the Bureau of Indian Affairs. Assistant U.S. Attorney Meghan N. Dilges prosecuted the case.

Koster was immediately turned over to the custody of the U.S. Marshals Service.