Stores with self-checkouts are already using it to detect theft. I know for a fact that both Walmart and Home Depot employ this. It uses both cameras and data from the self-checkouts to find behaviors such as concealing items or deliberate mis-scanning to cheat the system.
Home Depot's AI system falsely labeled me as a shoplifter when I was checking out. I bought some simple plumbing fittings and made the "mistake" of scanning one item twice (because I had two) and putting the other item in the bag without scanning it individually. It thought the second item was something else that I was trying to steal.
As soon as I made it to the exit, klaxons went off, orange lights flashed, and the shopping cart even locked up so that I couldn't push it out the door.
A receipt and bag check confirmed that I paid for everything in the cart, a terse apology was issued, and I was on my way. At least he didn't accuse me of theft, just wanted to check the bag because the system told him there was a potential discrepancy.
There are stories like this at Walmart, but with poorly-trained "Karen" employees who think the system is infallible and immediately start accusing shoppers of theft in front of other customers which has resulted in hurt feelings and threats of law enforcement over nothing. It has resulted in nationwide "re-training" of self-checkout employees.
Now I just get side-eye from the self-checkout hall monitors who stare at me when I'm checking out, sometimes getting into my personal space to look at my items as I'm checking out, but no outright accusations of theft.
The whole experience doesn't feel particularly friendly and the system doesn't seem like it's doing anything other than making customers feel "watched" and employees on edge for shoplifting that is false alarms most of the time.