The attorney representing a Skippack teen accused of stabbing his girlfriend to death is asking a Montgomery County Judge to remove from the record Tristan Stahley’s confession to State Police on the grounds that Stahely was not in the right mental frame of mind when he offered statements to investigators. Stahely told police he stabbed his girlfriend, 17-year-old. Julianne Siller and hid her body in a park near his Skippack Home on the night of May 25th. A judge has not ruled on the request to have the confession concealed. Stahley’s attorney has also asked a judge to move the case to juvenile court. Stahley is charged with 1st and 3rd degree murder. Julianne Siller was scheduled to graduate from Spring-Ford Area High School last June.