Originally Posted by BatLobsterRises
I always figured he just left his knife in the other guy. I mean this is The Joker we're talking about. He's shown to make knives appear out of nowhere like a magician in the movie. He's also good at making things disappear, like pencils and...Rachel.
Yeah, this is what I was thinking while reading the criticism.
The inspection they do on him once they finally catch him remarks that he's got knives in his pockets. He seems to be practically made out of them, which is part of his charm/scariness.