It was years ago that I saw it. I'm pretty sure it had to have been made in 2004 or earlier.

At least one of the main characters was a man (I think he was THE main but I honestly don't remember) and I think he was a cop, detective, etc. Anyway, he was looking into some sort of vigilante case or the vigilante showed up during whatever his investigation was.

I know there was woman, but I can't remember how important she was. I do know she had long brown hair, she was an older lady, late thirty to late forties, and I believe she had some sort of terminal disease.

I remember a quote, and that's really about it as far as it goes for the actual story. Something along the lines of "Anyone who harms a child deserves to die".

EDIT: The main character is not the vigilante. I remember being somewhat surprised by the identity of the vigilante, but I don't remember who it was.

EDIT 2: I vaguely recall the guy having light brown/ dark blond hair.

And there was a scene near the end that he was releasing all these kids from cages or dog crates inside of some building, a barn maybe.