When a thief takes a steak from the cooler and walks out the door, they don't know who that person is. And while they may have video of parts of this, they don't necessarily see enough to prosecute. (Acting like you're stealing a steak but not actually doing it isn't a crime. Shoplifting can be hard to prove; part of that proof means demonstrating that they didn't change their mind and just drop off the steak somewhere else in the store.)
When a thief takes a steak from the cooler and walks it up to self-checkout and pays for it as if it is a bunch of bananas with their credit card, they have identified that person. They have them on video at the self-checkout committing this crime.
It actually doesn't matter much if they leave the store with their bounty or not in this second case. The crime is already done by converting the steak into bananas.
In that scenario it seems to me that the best the thief can do is to "accidentally" ring up a steak as bananas occasionally and hope that if someone ever takes note that the past events will remain undetected.
That said, I'm pretty sure all of the self checkouts I've interacted with over the past several years would automatically flag such a "mistake". There are some things they're still bad at and they generate plenty of false positives but they seem to be reasonably good at identifying obvious "errors".
That said: I've never, ever weighed meat at self checkout. In fact, I've never had a cashier any weigh meat, either.
I've bought plenty of steaks in regular grocery stores, but each of those steaks (even the ones that they wrapped in butcher paper just for me after I selected them from the glass case at the back of the store) had the weight coded into the UPC that was printed at the time it was wrapped up (and weighed by the meat cutter).
There has no further weighing required for the register to know the price, so weighing a steak at the checkout is pretty bizarro-world behavior to begin with -- at least in my experience.
https://en.wikipedia.org/wiki/Universal_Product_Code#Number_...
There's already an scale that prints UPCs in the produce department for customers to use. I'll just put the package of steak on there, punch in 4011, and scan out my "bananas" at the self-checkout. ;)
(But they'll still know who I am. Walking out is cleaner, and has fewer steps.)
Honestly if you’re a thief this is just a dumb idea. Probably works for the original commenter a few times fine. But it’s way too obviously and intentionally theft. You need to come up with something you can claim was an honest mistake.
Find another item that sounds similar but is cheaper and use that upc. If you’re keying in the upc, on a scale or something, then find one that’s cheaper but off my 1 digit or something where you can say it was a typo and you didn’t notice. Those kinds of things are more defensible. None of us have been trained to be a cashier so honest mistakes are a strong defense to any claim of misconduct.
Anyone just buying bananas and steaks is going to look suspicious fast. So rotating the banana for other things is key. Having a mixed bag of purchases where the steaks are always just accidentally unscanned or misscanned.
The facial recognition thing isn’t really in the picture for this minor type of crime. Law enforcement doesn’t have easy access to it as Hollywood would lead you to believe. Its use is reserved for higher profile crimes. You’d have to really be running a steak stealing criminal syndicate for this to happen. Before that, retailers would have already started forcing different procedures for the steaks. Like locking them up or pay at the butcher stand.
One thing facial recognition can do, if used properly by the retailer, is flag you and alert the store to put extra eyes on you every time you enter the store. There’s an increased chance they’ll confront you in the act or otherwise scare you off of it.
But at some point, they do start to care.
Stealing fifty dollars worth of steaks on 20 different occasions (every couple of weeks, say), with video and transaction evidence of the acts happening over and over again? That's a lot easier to prove, and in many states adds up to a nice juicy felony.