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Justice News

Department of Justice
U.S. Attorney’s Office
District of South Dakota

Friday, August 2, 2013

Waubay Man Found Guilty Of Murdering Daughter

United States Attorney Brendan V. Johnson announced that Mario Contreras, age 35, of Waubay, South Dakota, was convicted of Second Degree Murder and Assault Resulting in Serious Bodily Injury as a result of a federal jury trial held in Sioux Falls, South Dakota.

The charges carry a maximum penalty of life imprisonment, a $250,000 fine, or both; 5 years of supervised release; and a $100 special assessment. The murder charge carries a mandatory minimum sentence of 30 years in prison. Contreras was indicted by a federal grand jury for the charges on August 14, 2012.

The victim was born on December 31, 2009, and was murdered by her father on January 9, 2012, just after she turned 2 years old. The victim’s mother and father were never married and were no longer close. The defendant was not very involved in the victims’ first year and a half of her life. On January 4, 2012, the victim’s mother asked Contreras if he could watch her for a few days. Contreras had custody of the victim from January 4th through January 9th, the date of death.

Contreras told investigators that on January 9th his daughter was having a cup of water and a banana and he left the room. He said that is when she fell off the chair and sustained the injuries that cased her death.

The Assistant Medical Examiner of Ramsey County, Minnesota, who performed the autopsy, discovered 18 round bluish-colored contusions on four sides of the victim’s head, indicative of blunt force trauma. He concluded that the multiple contusions and resulting subdural hematoma could not have been caused by a single fall from a chair and that the cause of death was a homicide. Another government expert on child abuse also concluded that the injuries were inconsistent with falling from a chair or table. An additional expert for the government determined that there were small hemorrhages to the retinas and concluded that the child was beaten. Two government experts testified that the chances of such a short fall causing death were “one in a million.”

The trial commenced on Tuesday morning, July 30, and concluded Thursday evening, August 1. After approximately two and a half hours of deliberation, the jury returned a verdict of guilty of Second Degree Murder and guilty of Assault Resulting in Serious Bodily Injury.

This case was investigated by the Federal Bureau of Investigation, the Sisseton-Wahpeton Tribal Law Enforcement Services, and the Bureau of Indian Affairs. The case was prosecuted by Assistant U.S. Attorneys Thomas J. Wright and Jay P. Miller. A presentence investigation was ordered and a sentencing date is set for November 2013.

The defendant was remanded to the custody of the U.S. Marshals Service.

Updated June 22, 2015