MITCHELL, S.D. (AP) - The South Dakota Supreme Court will hear an appeal of a judge's decision to toss out an alleged confession in the killing of a Mitchell teenager.

Prosecutors say Maricela Diaz waived her right to remain silent when she was questioned about the November 2009 death of 16-year-old Jasmine Guevara. But Judge Tim Bjorkman ruled last August that police failed to properly inform Diaz of her rights.

Diaz was 15 years old at the time of Guevara's death but is being tried as an adult. She's now 18.

Prosecutors want the state Supreme Court to overturn Bjorkman's ruling. The Daily Republic reports that justices will decide after both sides submit briefs.

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

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