SIOUX FALLS, S.D. (KELO) -- We have an update on a South Dakota cold case dating back to 2001. When police arrived at Pam Dunn's Watertown home that December, the door was locked, her purse was on the table… but Pam was nowhere to be found.

More than two decades later, authorities are still looking for her. Pam's boyfriend was the last person to see her alive.

He's serving a life sentence for kidnapping her, but recently the case was reopened, because his attorney claims the sentence was 'illegal.'

The attorney for Dave Asmussen filed a motion to modify his client's life sentence.

According to court papers, Ryan Kolbeck is asking the court to, quote, "correct the illegal sentence currently in place."

Kolbeck claims the judge erroneously wrote in his judgment that Asmussen made a volun

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