Is this an AI article? It's quite a mess of text.
Also, who in the world would want thieves locked in WITH THEM? Oh, I had an issue with some property being stolen, now I turned it into an assault and possibly murder.
Additionally, you're assuming the cops are going to show up promptly. What happens if it takes them 30+ minutes or longer. Just chill out with a bunch of criminals in your store?
What happens if a fire starts and triggers it, locking everyone inside? You need a PROPERLY LABELED fire exit so you don't kill people. Guess what criminals are going to use to get out when that gate shuts.