What right?
Sure there is. "I would prefer not to be treated like a criminal in your store". Reason enough?
No, not reason enough. You are being unreasonable. If you act like a thief, be prepared to be treated like one.
There are many, MANY other ways to accomplish that. For instance, for big ticket items, you hand the person a tag to pay for the item, and then the customer turns in the tag at a loading dock. Not to mention that most theft is done by employees.
It doesn't matter whether there are other ways to reduce shrinkage or even whether or not most theft is done by employees, which I agree that it is. What matters is that the store has instituted an anti-theft policy, which may be one of many (seen or unseen by the general public) designed to reduce shrinkage. That benefits the store, the shareholders, and the public.
He tried to leave--which is attempted escape his right Fixed that for you.
This is escape under Ohio law. If a storekeeper has detained you and you try to leave, you have attempted escape, which is a criminal offense.
I wasn't aware that being a jerk was illegal nowadays. We're going to have to build more prisons!
It's not illegal. But when this man chose the course of his actions, he made some mistakes. Larger, more serious mistakes followed. Those actions have consequences.