I think the better question, is did Arpaio arrest anyone who was present in our (their) country, legally, and not a criminal?.... which is a yes.
Were they arrested or detained until they could find out if they were legal residents?
I'm genuinely asking since I don't know much about Arpaio's actions.
I'm sure iit's common for cops to detain or arrest the wrong guy.
Nobody likes to be in handcuffs when they have not broken the law but that doesn't mean there's always some kind of ill will behind the arrest.