Complex sentence: Upon hearing Chilton's voice, Lass experiences a false memory implanted by Lecter during her imprisonment of Chilton tormenting her: in a moment of distress, Lass impulsively draws Crawford's gun and shoots Chilton in the face through the mirror.
Split into simpler sentences: Upon hearing Chilton's voice, Lass experiences a false memory implanted by Lecter during her imprisonment of Chilton tormenting her. In a moment of blind rage, Lass draws Crawford's gun and shoots Chilton in the face through the mirror.