Kick the Ballistics
Student Jane Herzfeld was fatally shot with the Glock service revolver serial killer 3XK stole from Ryan. Her only dodgy ex, Finn McQueen, has an alibi. Phone records show she was in contact with undercover narcotics detective Seth Carver, who forced her to inform on tutoring pupil Ben Lee's dad Clifford's Chinese drug mob. Castle ingeniously finds some missing links trough prison records.
