They say hell hath no fury like a woman scorned. Well, you're about to meet a lot of women who say they were scorned by a so-called internet casanova who pretty much turned the country into his own personal pickup bar. But one woman decided to bait a honey trap to catch him with what seems to be his favorite thing. Money. Other people's money. So, how do you catch a thief of hearts with nothing but a tax return? Amy robach has the story. This is ray. Hi, ray. Hello. Ray is a big filmmaker. Reporter: Say you happen to run into a man named ray holycross and right away he tells you something incredible. Someone mugged him. Can you just briefly tell what happened? Briefly -- ah, a rather short man came up to me and he had a rather large gun. A gun? A gun, yes. Are you serious? Reporter: You take pity on him, right? As you're about to see, plenty of people all over the country claimed that would be one big mistake. When I say the name ray holycross -- what's your reaction? It gives me chills. Makes me feel sick. Reporter: Jen clark says believing ray holycross helped make her life a holy mess. Just two years ago, she was on top of the world. An independent career woman working for a software company in portland, oregon. She had a nice home with a swimming pool and was raising her 12-year-old daughter on her own. Obviously, everybody wants a prince charming. Reporter: But then you thought you met prince charming? Yeah, I did. Reporter: Prince charming aka ray holycross, a 29-year-old heartthrob, contacted jen via the website "plenty of fish" and in no time, she says she fell hook, line and sinker. Hi, babe, I love you. He was attractive and charming. Well spoken. He said he was a director. Told me that he worked on the show "24." And movies. Reporter: So, he was exciting. Oh, yeah, he was -- you know, it was super exciting. Reporter: So sure she'd found the one, she says when ray told her he'd been mugged and lost all his luggage and credit cards, jen opened her heart. Right away, they were living together, sleeping together. But she says, not exactly spending together. I bought him clothes and took care of him because I cared about him. I supported him, I fed him. I -- you know -- Reporter: You sound like his mother. Yeah, I was his mother. Hey, it's me. I just wanted to say I love you. Bye. Reporter: For a whole year, jen says ray piled up the sweet nothings while she emptied out her savings. What do you say to people who think there were red flags everywhere? How did this woman not know what was happening? I really truly just believed him. And I think every girl wants to believe that there's some guy out there who loves them that much. Reporter: She may be right. Show of hands. How many of you would say ray deceived you? All of you? We went searching far and wide and brought together those left in his wake. St joe, michigan. Chicago, illinois. Salt lake city, utah. Reporter: Some call him a cad, some call him a crook. All say you couldn't believe a word. Knight in shining armor without money, is that a fair statement? Reporter: A first class mooch. They say ray told them similar stories. I was willing to help him because he told me he had been mugged and that he had nothing. Reporter: They claim holycross took whatever they would give. Free food, free rent, sometimes even sex. Until the day he suddenly vanished. What did ray take from you? My ipad. My daughter's ipod. Around $4,000 at least. Just my time. But he gave me the ability to know that my gut instinct is number one. Reporter: From jilted to vigilante, they decide to turn the tables. Figuring, if ray found his women on the net, that would be the place to sound the alarm. They created this website and a facebook group to get the word out to ray's potential new girlfriends and locate old ones. How many girls are we talking about? Oh, we called 45, 50 women. Reporter: One of them was jen clark. They said, I supported ray for however long and then he stole from me. Reporter: You believed them? I believed them. Reporter: But still not enough to bail on ray. Lonts monthers later, she lost her job and says ray told her they could start over in chicago and he'd foot the bill. Hold on for a second. Reporter: She gave up that beautiful home with a swimming pool and says she woke up one morning only to find all the warnings come true. Ray was gone, along with her atm card. She told the police he stole $900. I lost, not only just myself, but dignity, my faith in hum humani humanity, but I lost my daughter, who now lives with her dad. Really, I lost everything. "On your side" investigator thom jensen is here with the story of ray holycross. Reporter: But now, ray was on the run. With the news starting to spread locally. Police across oregon are looking for this man. Reporter: And nationally. He's being called the internet casanova. Reporter: Even ray's own brother had had enough. He digs holes and gets into lies and it's just a nonstop thing. Reporter: But where exactly was ray? He's a filmmaker. He does edits, you know, hollywood production and everything. Reporter: Hard as it may be to believe where he was. He was on camera. We're about an hour away from boise. Reporter: Incredibly, ray had crossed paths with that man we saw earlier, who was driving cross-country and recording the whole trip on video. And there he is, apparently telling the same old stories. Can you just briefly tell, like, what happened? A rather short man came up to me and he had a rather large gun. A gun. Yeah, yeah. That's crazy. Reporter: Ironically, the man's video blog was called "the truth is." Do you remember ray? Still here. Reporter: The road trip turned to road kill when ray arrived in mishawaka, indiana and met theresa bridgegroom. With a name like hers, he might have thought he had found the perfect foil for his next romantic romp. He had no idea he had just met his match. Who is ray holycross? He's just scum. Reporter: Only days after meeting him through mutual friends, theresa invited ray to live with her and her 10-year-old son. She says she even let him use her chevy to go to his supposed tv job out of town. But this reality show should have had a tv-ma rating. Theresa laered cell phone videos of him with other women having trysts in her truck. It just makes me sick that he did that in this truck. Like, I don't even want the truck. It just disgusts me to know that he did it. Repr: Something else disgusted her, too. A receipt from a local pawn shop. She says he had sold her expensive camera. I thought, no, I'm not letting him get away. There's no way wassing igoing to do that. Reporter: So how do you catch a rat? With cheese, courtesy of the u.S. Treasury. So, what did you do? I had texted him and told him I got my tax check. Reporter: That tax refund, fresh money in the bank, drew ray back like a moth to a flame. A half hour after ray arrived at the apartment, theresa quietly called the cops. Within a couple minutes, they were pounding on the front door. Well, tonight the man dubbed the internet casanova has been busted. It felt great. I thought, how many women and cops, police departments were saying they were looking for him, trying to track him down. All I had to do was say, I got my tax check and then, within eight hours, done, gone. He's locked up. Reporter: Tonight ray holycross is sitting in this jail having plead guilty to a charge of theft. He declined to speak with "20/20" and is awaiting sentencing in may. The maximum time he could get? 18 months. What should happen to ray? He should be in a mental institution. Reporter: In the meantime, these women simply want to warn perspective online surfers. Look out. They believe whenever ray holycross gets out, he could be looking to break your heart, and your bank.