From "Batman: Smack in the Middle (#1.2)"
That was the one hole in your plan.
Well there are gonna be some holes in you, Batman!
[pulls the trigger on her revolver twice but nothing happens
Foolish girl. You were so bent on your murderous scheme you failed to notice, in the Batmobile, I burned off your revolver's firing pin with a hidden Bat-Lasar-Beam.