Best Role Ideas?

[Caboose]

You

Have a loud whistle

The town watch you are a part of has asked you to keep an eye on the neighborhood, and has given you a loud whistle to blow when you see any criminal activity.

You may choose one person to watch. If you see anyone trying to break into that person's house, you blow your whistle, and the criminal is forced to either run away or, if he dosn't do that, you have a chance to see who he is.

You win with the town.

(Combined doc/watcher variant; if someone tries to kill a person you're protecting, he will be PM'd a choice; EITHER he runs away, in which case the kill fails, OR he goes ahead and kills anyway, in which case the kill succeeds but you find who the killer is. Either way, it's the killer's choice if he would rather be prevented from killing or identified.)

Would this apply to non killing roles like roleblockers and cops?