Even as McEwan heard the overwhelming evidence against him, she believed in Mathews. She remembers that McEwan used to wink at her when he passed her in court. She says she believed that all the charges, all the evidence, were some kind of mistake.
"He told me that he was a race car driver, that he had money that was tied up in a trust fund," says McEwan.
After 18 months in prison, Mathews was released. Two months later, he and McEwan got married. McEwan says she was happy and in love.
Mathews persuaded her to refinance her property and build on it. As construction began, she got the first hint that things were not what they seemed. She found out that Mathews was cheating on her and that he was stealing her money.
At this point, McEwan lost her house to creditors. And she couldn't have her husband arrested for using up their joint account. She filed for divorce and lived on the charity of friends.
"I hit bottom," she says. "But I didn't bounce back. I stayed there for a couple of years."
But after years of hard work, McEwan got her life together, becoming a mental health nurse. She recently received her master's degree in psychology.
Private investigator Walt Zwonitzer first encountered Mathews in 1981: His marriage to Diane McEwan was over, and Mathews had wasted no time finding new victims.
A widowed schoolteacher came into his office and said that her fiancée had disappeared with her Corvette, her pickup truck, some money. The missing man was Mathews.
In the more than three decades that Zwonitzer has been a private investigator, he's hunted down his share of con men. He says he's never met one quite like Mathews.
"There are literally dozens if not hundreds of women and businesses that have been flim-flammed by Matt Mathews," he says.
Zwonitzer had plenty of time to become an expert on Mathews' modus operandi: He trailed Mathews off and on for 17 years.
In part because of Zwonitzer's work, Mathews landed in jail for theft two times more more, in 1983 and 1990.
Most of the victims were women, but Mathews had even conned a bicycle manufacturer into donating an expensive bike to an imaginary child who was dying of leukemia.
Zwonitzer thinks Mathews is a sociopath.
Mathews' half sister Barbara, who hasn't seen him for 25 years, paints a very different picture of the sibling she had always called Eddie. When Eddie was 2, his parents divorced, and Barbara says that she has been told that his father gradually drifted out of his life.
Eddie's mother remarried, and Barbara was born when he was 9. She remembers an apple-pie and ice-cream middle-American childhood growing up in the suburbs of Ohio. She says she and her half brother were close.
When the boy was 14, his mother died of leukemia, leaving hi to be raised by his stepfather. Barbara thinks that their mother's death deeply affected her half brother, whom she remembers as talented and smart.
Mathews himself blamed his stepfather for his life of crime, and said that he had emotionally abused him. He, however, took the name of his stepfather, Matt Mathews.
Psychiatrist Park Dietz, an expert on the criminal psychology, doubts childhood holds the clues to what makes a con man like Mathews tick.
Dietz says the stories of abuse were a ruse to gain sympathy. He says that Mathews' charm fits the profile of a con man.
"That's a classic feature of people who are emotionally empty, Dietz says. "They find out what matters most to someone. They learn their weaknesses. And then they exploit it to the fullest."
And, says Dietz, rehabilitation usually doesn't work.
What happens when Mr. Wonderful faces a jury? Find out in Part III: Mr. Mathews Goes To Trial.
Produced by David Kohn