PIERRE, S.D. (AP) - Prosecutors are asking the South Dakota Supreme Court to overturn a lower judge's decision to toss out the alleged confession of an 18-year-old girl charged in the killing of a South Dakota teenager.

Judge Tim Bjorkman ruled in August that police had failed to properly inform Maricela Diaz of her right to remain silent while questioning her in the November 2009 death of 16-year-old Jasmine Guevara of Mitchell. Diaz was 15 at the time.

Prosecutors argue that Diaz voluntarily waived her Miranda rights and say "the inappropriate suppression of (her) statements significantly damages the state's case."

The Daily Republic reports the defense has until Friday to respond to the appeal.

Diaz's boyfriend, Alexander Salgado, pleaded guilty to murder in the case in 2010 and is serving life in prison.

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