Transcript for In alleged scheme, couple, homeless man accused of raising $400,000 'on a lie'
I was glad to offer, you know, to help them. Somebody needed it. Reporter: It was the good samaritan story that captivated the nation, seeming almost too good to be true. And authorities now say, it was. I was driving down 95 and ran out of gas, so I pulled over on to the side of the road. Reporter: Kate Mcclure stranded on the outskirts of Philadelphia when homeless veteran Johnny bobt Jr. Came to her rescue. He walked up and said, get back in the car, lock the doors, you know, I'll be back. Reporter: Spending his last $20 to buy her gas. You know, she needed the help and she took the help. Reporter: With the title, paying it forward, the gofundme page and the story of Bobbitt's selflessness went viral. The couple's original goal of $10,000 quickly ballooned to more than $400,000. It's like winning the lottery. Reporter: But today, a shocking twist. The entire campaign was predicated on a lie. Reporter: Authorities say it was all a coordinated scam from the start. The cover photo on the page, staged. All three of them were in on the elaborate hoax. She did not run out of gas on an I 95 off ramp and did not spend his last $20 to help her. Rather, they conspired to pass off a fake feel-good story that would compel donors to contribute to their cause and it worked. Reporter: All three charged with conspiracy and theft by deception. Their attorneys had no comment today. This case, you're talking about over $400,000 and so this takes it to a different level. And the amount of money at stake is why the crime got elevated to the level that it's at. Reporter: Prosecutors now claiming the idea could have come from Bobbitt himself. In 2012, Johnny Bobbitt posted a remarkably similar story on his Facebook page out of North Carolina where he reported that he helped a woman who had both ran out of gas and had a flat tire at a Walmart, spent his supper money to get her on her way and fix her flat tire. I don't think that's a coincidence. Prosecutors are taking this really seriously. Because this has gone from a heartwarming story to a sad, troubling story, and so effectively, they're having the book thrown at them. Reporter: At one point, Mcclure and Bobbitt sitting side-by-side detailing the heartwarming story of how they came to meet. Mcclure telling ABC that she and her boyfriend were moved by the homeless vet's generosity so the couple went back to visit Bobbitt where he was living under a bridge. When you got someone that's, you know, coming back to help you, you know, it makes you feel good, you know? That someone's actually showing a interest in you. Reporter: The story now in question would then lead to Mcclure and her boyfriend returning the so-called good deed to Bobbitt. We were thinking what if we started a gofundme for this guy, just to get him, you know, off of the streets even for a weekend. Reporter: Authorities today saying the truth behind the alleged conspiracy trickled out less than an hour after the page went live. Mcclure, in a text exchange with a friend, stated that the story about Bobbitt assisting her was fake. Specifically, she wrote, "Okay, so, wait. The gas part is completely made up. But the guy isn't. I had to make something up to make people feel ba so shush about the made-up stuff." Reporter: And as we now know, the inspiring tale pulled the heart strings of thousands across the country. By the middle of March, d'amico and Mcclure squandered the vast majority of money. Reporter: As the money poured in, Mcclure and d'amico stipulated the funds would go to buy Bobbitt a new home which Johnny will own and the dream truck he's always wanted. We have meetings set up with us and a financial adviser and a lawyer, obviously, because it's gotten to this point. We're just going to really go off of them and what they say. Reporter: But this August, the bubble began to burst when Bobbitt accused the couple of stealing his money. I have to ask them for everything. It was kind of -- in the beginning, it was a joke. Like they were like my parents. But the joke stops being funny after a while. Reporter: Alleging they bought him a camper that they parked on their property and of the $400,000 plus, he says he only got $75,000, claiming the couple spent the rest on themselves, money that allegedly went into funding a lavish lifestyle, one that they flaunted on social media, going to Vegas, visiting the grand canyon on a private helicopter tour. Mcclure seen here with a Louis Vuitton bag, gambling. Then in late summer, the legal woes between the trio started to raise questions. The question remains, what happened to all that money and where did it go? Reporter: According to court records, on August 27th, d'amico allegedly texted Bobbitt saying, in part, I say I get rid of my team of lawyers, you get rid of yours, and Kate and I will write you a check. Seriously. Prosecutors claiming the fantasy-filled hoax quickly turned into a nightmare. Bobbitt filing a civil suit against Mcclure and d'amico eventually igniting a criminal investigation. We're here today asking the defendants where the money went. Reporter: With much of the money missing, the couple's attorney said in New Jersey court that they promised to provide an accounting of the fund. I would urge anybody to withhold judgment until that's been made public. Reporter: But when the judge ordered the couple to return any remaining money into escrow, their attorney said there is nothing left. The next day, police executed a search warrant on the couple's home, towing away this BMW and taking out bags of evidence as d'amico stood in his yard, swinging a golf club. Today, prosecutors say it was that legal battle that motivated them to look into the alleged scheme. If they hadn't started fighting over the money, would they have gotten away with it? There's a good chance they might have. Reporter: In a statement to ABC news, gofundme writing in part that while this type of behavior by an individual is extremely rare, it's unacceptable and clearly it has consequences. Committing fraud, whether it takes place on or offline is against the law. The company also stating that campaigns with misuse make up less than 0.1% of all campaigns. The company today saying all donors will receive a full refund. What I needed was money and what I received was love. Thank you! Thank you. Reporter: But crowd sourcing websites have raised billions of dollars for good and with the holidays approaching, there are steps you can take to help make sure that your money is going to the right place. The better business bureau recommending you learn all you can about the charity or individual. Do a reverse image search on any photos used in the campaign. And caution that scammers often put up multiple campaigns across several platforms. There's definitely an element of buyer beware. You are not dealing with organizations that have tax exemptions, for example, that have been vetted. You're dealing with people. Reporter: Tonight, all three accused liars who are said to have preyed on America's generosity now awaiting their trial. For "Nightline," I'm wit Johnson in mt. Holly, New Jersey.
This transcript has been automatically generated and may not be 100% accurate.