Maybe not, but you don't have a right to arrest someone without evidence. No one does.

[ She holds her hand out as if she's metaphorically holding out another suggestion. ]

There are plenty of people who would bring in people just for the glory of being treated like a hero or hoping to get rid of someone for good without having blood on their hands. I'm not just going to trust every person who brings me an unconscious body, and I can't arrest someone without evidence. You find me a witness, then we'll talk. Otherwise, I can take his information but that's the most I can do.