Tonight, you don't need us to tell you this was tax week. But are your tax dollars being spent by others who claim they're hurt? Come on down. You're in for a showcase showdown. Why are people too... See More
Tonight, you don't need us to tell you this was tax week. But are your tax dollars being spent by others who claim they're hurt? Come on down. You're in for a showcase showdown. Why are people too hurt to work showing up on game shows and going on vacations? Cecilia Vega tracks them down. Reporter: Say you're in the audience of "The price is famous words. Come on down! Reporter: You do what the man tells you. Fast, like this woman, Cathy Cashwell. 1,375 dollars! Cathy, c'mon up here! Reporter: But a fortune in fabulous prizes wasn't the only thing Cashwell was collecting. True to her name, Cashwell was also raking in three grand a month in workers' comp, claiming an on-the-job shoulder injury left her totally unable to stand, run, reach or grasp. There you go, good luck. Reporter: But there she is, spinning that big heavy wheel, not once, but twice. Wow, who knew drew Carey was a miracle worker? ♪ Cashwell is just one of the countless people accused of faking an injury to collect on disability payments. Experts estimate bogus injury claims cost taxpayers hundreds of millions of dollars a year. And questionable claims are up 24% from last year. Moochers like Valerie Scroggins, a bus driver who claimed a severe shoulder injury prevented her from getting behind the wheel. But that's her, behind the drums. Investigators caught her on camera playing in her punk band. Later, she pleaded guilty to fraud. This airline employee claimed her ankle was so mangled she couldn't stand, squat or bend yet here she is, looking like she's eligible for the NFL draft. Her case was settled after she was busted on tape. The same goes for this guy who said he hurt his back while working for a major food and beverage company. His physical restrictions? Bending, twisting, turning. Investigators gave him a perfect ten, for cheating. ♪ Reporter: It takes a secret agent of sorts to catch injury imposters in the act. I always loved James bond. You wanted to be a spy? Absolutely, absolutely. Reporter: And in this cat and mouse game, nobody does it better than chicago-based private eye bob Kiehn. He's a moocher-busting 007 armed with a minivan packed full of spy gear. Tricks in the trunk. What you got? Full camo, just in case. Reporter: His targets often try to evade detection, but once caught red-handed by our master of disguise, they often settle their cases. Like this car company worker, marwan Khouri, who reported severe back and neck injuries, yet was still able to wield a pick axe. His lawyer says the video does not reveal the extent of the injury. But from here, it looks like we've got a gold digger. Or this steelworker, cashing in on a left shoulder injury while playing with power tools. He's claiming to his employer limited to no use of his left arm. And to that you say? Busted. All right, let's get her. Reporter: To see the expert in action, Kiehn takes "20/20" out on a case as observers. Staking out a supermarket worker whose doctors say should be wheelchair-bound. Her boss wants to know how much she's really hurting. We're here to document how she really moves. Reporter: We know our mark has a doctor's appointment, but today we're the ones doing the check-up. After waiting for more than two hours, we spot her. And not a wheelchair in sight. We can't show her face because the case is still active. And, speaking of active. The chase is on. Now the fun starts. I'm holding on! Reporter: We're burning rubber to stay on her tail. Following her car as it barrels down I-88, where apparently speed limits are just a suggestion. Five over the speed limit. Five or -- Five. Reporter: After pursuing our target for 50 miles, we catch up with her at a doctor's office northwest of Chicago. Remember, her doctors say she should be confined to a wheelchair, but there are still no wheels in sight. Her case is pending in the courts. What do you think about people like that, people who think they can beat the system? It's those people that are raising the insurance premiums. That's why I do this. Reporter: Catching injury scammers the old school way clearly takes a lot of effort. But sometimes you don't even have to leave the office, because who needs a secret agent when the bad guys are blasting their behavior on social media? Remember Cathy Cashwell, the enthusiastic contender on "The price is right" who claimed to be totally disabled? She posted her vacation pictures online. Here she is flying high, literally, zip-lining and hang gliding on Facebook. In a statement to "20/20," Cashwell said that despite how she looks in those images, she was, quote, "Hurting the whole time." But she was collecting the whole time too. And last year, thanks to those damning depictions, she pleaded guilty to fraud. Fraud is a fancy word for telling a lie. It's stealing with your pencil, as opposed to stealing with a gun. Reporter: It turns out the "Price is right" double dealer isn't the only one to give herself away online. And it may not get any lower than this. Scores of former New York City cops and firefighters indicted for falsely claiming they had PTSD and anxiety as a result of the September 11th terrorist attacks. I can only express disgust at the actions of the individuals involved in this scheme. Reporter: Individuals like glen Lieberman, who said he was so crippled by mental illness he couldn't leave his house. But he's looking far from adrift in this Facebook photo released by prosecutors. His lawyer claims this photo was taken before Lieberman became sick. Then there's Louis Hurtado, who allegedly collected almost half a million bucks for his depression from a back injury. Investigators found him online, running a karate school and teaching black belt. To quote the karate kid's Mr. Miyagi -- No such thing as bad student, only bad teacher. Reporter: And authorities say this man, Richard Cosentino, claimed he was too depressed to go outside. That must mean he caught this giant fish in his living room? One of the most brave -- brazen defendants -- allegedly, lying about suffering from depression. And then collecting almost $150,000 in disability. Meanwhile, prosecutors say he was living large with stolen money, taking exotic trips to places like Indonesia. They keep paying us, they keep downloading money every single week, we're getting e-mails that said congratulations, you have money. Hey I'm Cecilia Vega from 20/20. Reporter: We wanted to ask Lamantia about his seemingly remarkable recovery. The prosecutors are saying you're essentially a cop who scammed the system. That's not, I'm not a cop -- You were a cop, at one point. Why don't you give me a quick comment and we'll get out of your hair. I'm sorry. I really can't. You know they say that -- As you can see, my hair is long and you're in it. You claimed to be so mentally ill that you couldn't work, and yet you were still working on the side, basically defrauding. Hold on, I just can't -- I'm on the phone right now. Reporter: Lamantia and the other defendants in the case all pleaded not guilty. Despite the many who have been busted trying to cash in after claiming to be hurt, there are thousands more willing to give this well-worn scheme a shot. What do you have to do in order to pull this off? The best way and only way of beating the system is completely staying in your house, not leaving for three to five years. Because anything you do outside of that and we're there, we're going to get it.
This transcript has been automatically generated and may not be 100% accurate.