Christopher Scott Wilson again pleaded not guilty today to the murder of Mackenzie Cowell, as he was rearraigned on a charge of first-degree murder.

At the same Chelan County Superior Court hearing, the scheduled May 31 date for the start of his trial was canceled, with a new date yet to be assigned.

Wilson, 30, had been charged with second-degree murder in the 2010 death of Cowell, a 17-year-old Wenatchee High School senior and hairstyling student. Chelan County Prosecutor Gary Riesen entered the new charge April 12, saying the injuries inflicted during the murder pointed toward premeditation — one of the prerequisites for a first-degree murder charge.