The parents accused of murdering a four-month-old Alta Vista baby have pleaded not guilty. According to court documents, both Zachary Koehn and Cheyanne Harris entered written not guilty pleas this week. A trial date has not been set. Their baby, Sterling, was found deceased in his infant swing Aug. 30. A forensic study indicated the child hadn’t had a diaper change, bath or been removed from the swing in over a week. The investigation indicated the parents’ account of the death was inconsistent with the findings of the autopsy and investigation. The complaint states that “The cause of death was a failure to provide critical care. The facts of this case go far beyond neglect and show circumstances manifesting an extreme indifference to human life.”