Transcript for Holiday Food Heists
Tomorrow is Thanksgiving a day to feast but it's also the start. Of the multi billion dollar holiday shopping season Black Friday is now changed that a black Thursday and it also marks the beginning. Of a lesser known more sinister holiday tradition. Turns out there with a huge flood of shoppers who come to buying. Comes a huge flood of shoppers with other plans and it may end up costing you. Here's ABC's John Donvan. It's that warm and Fuzzy time of year again. That open up your wallet time of year again from now until Christmas on the front lines of the American consumer marketplace. But it is also time -- you know for a lot more of this the theft that goes on spring. Summer and fall at a cost to the retail industry of 35. Billion dollars last year. And did you know it really starts -- now in the holiday season. And in the supermarket industry where the story is really only make a few cents on any one item and it places like the big -- in Wilbraham Massachusetts they put pictures like this on the. -- these are some of the more notorious folks that we caught stealing some of them are. This -- -- a -- flam artists. The loss to thieves nationally for supermarkets -- to almost six billion a year. And that cost has to be made up somehow. You know we are profitable. We have to charge more for what we're selling. But get ready for -- more surprising number of all of the -- that occurs in supermarkets nearly 40% of it is done by insiders employees. And it takes place in one place the check out. Watch how this works and overhead view of the cashier. Items traveling past the bar code scanner see that red target that is a Turkey. And what's happening right now is that the cashier is subtly jumping around the scanner so it's not actually being rung up as a charge. Although it is mixed in with other items that are now with the turkeys -- is really see a spike as many as four times more turkeys I stood in November and December than in the rest of the year combined. I thought maybe I'd give it a try -- what are you betting. -- -- All right so what happens and so then I was on camera taking the role of cash here. To see if I could beat the system and here's what I did I legitimately scanned most of the random stuff and picked up. But I jumped the staffing over the scanner. And the napkins. And of course the Turkey. But who was actually watching this video and analyzing it who was responsible for detecting. A Turkey -- here you see he's hanging on to stuff and and target and the customers his grandmother exactly that this is my lake -- The cheating cashier's worst enemy it -- -- -- -- that red target means he -- exactly. -- he -- -- -- lift the company that invented the software now in use of hundreds of stores. And it's what's putting those targets on the turkeys in the other items that. Their analysis shows with skipped over or around the scanner in a process known as sweet Harding. Well what's called sweetheart because it's on the cashier -- my friends family members fellow employee. He might sweetheart. I can give -- things for free. -- -- -- in typical profile. Of the -- the dishonest sweet Carter cash here there's the one that. Start from the very first week that they start on the job they're already sweetheart and part that's why they took that. And then there's also the great employees been with us for ten years -- -- which -- upon time and you come discover that part of the reason for that is because she's been skimming off the top for years. Of course in a world where we are being watched more and more there are cameras everywhere. This just means were being watched even more now as ingenious as this is. Contributing to the Big Brother -- -- nation of our culture well you know the cameras had been there. So we're not adding cameras I think what we're doing is helping with unemployment and keeping businesses afloat. And the cameras aren't just catching Turkey's it's -- so many things caught with the help these cameras and his software. Which -- seeing an 80% increase in -- around the holidays. Billions in stolen and sweet hearted boots there's a Turkey it's coming out. Stuffing ingredients. -- greater freedom when she has bought -- -- exactly got scanned yet yet inherits got -- but this target says she's still in the Turkey. She may have she may have seen -- the -- -- on this part of it -- and covered up from them just face the -- of the other way. So for somebody who sang happy Thanksgiving -- when you see that Turkey being stolen. They have to sell fifty more turkeys to make up for the one that was given -- for for. I -- more read about what happens to the people who get caught. And while she was reluctant to discuss the actual incidence of insider theft in her establishment. She said everybody is told when they start here. That yes they are on camera when we hire folks -- following -- -- -- -- stores but what happened when they watched me I wondered. The system analyze my moves from up above and when I get those three red targets well let's see. One. -- Three busted. Happy Thanksgiving not I think if I'd really thought I could get away with this I'm John Donvan for Nightline in Massachusetts.
This transcript has been automatically generated and may not be 100% accurate.