 A 13 @-@ year @-@ old Jake Gyllenhaal , son of the episode 's director Stephen , made one of his earliest acting performances in " Bop Gun " as Matt , the young son of Robert Ellison . Williams and Homicide regular Richard Belzer were acquainted from a HBO comedy special they both appeared in , although the two had never acted together before . The two often joked between filming takes , except for during Williams ' most dramatic scenes . The episode also featured Vincent Miller , an actor who worked primarily in the Washington , D.C. area , as Tweety . 
