"Oh, no, Sweepers are human! ...I mean, they may not work exactly like most humans anymore, but they count as human enough to be allowed inside the City."

The City's pretty particular about the kinds of things that are allowed to do mass murders. Humans good, Abnormalities bad.

"Halloween is... definitely a holiday of some kind, I've picked up on that much. And costumes are involved. And I think there's also supposed to be candy?"