What's wrong with using /disturbance?
If it doesn't give enough WL then why not suggest making it give much more WL if done inside a riot area?
The main idea behind my suggestion is to make it easier for new Criminals to get wanted. We don't want them to type anything in order to get wanted, just staying inside the riot area for 20-30 seconds would be enough to realize that X criminal is at the riot area for a purpose, which is to participate in getting wanted level.