Batman: The Long Halloween Animated Film Voice Actors Cast!

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Maybe I missed it, what was the end credit scene?

Green Arrow and Flash show up at Wayne Manor.

Batman always has his own code.
Letting her go at the end didn't seem that big of a shock.
Batman's sense of justice, doesn't always align with that of the police.
After all, Batman is a vigilante.

I think with his sense of justice and guilt over Alberto's death he'd feel almost compelled to at least do something.