They come in many shapes and sizes, but ponzi schemes have one thing in common. The investors are almost always the big losers, and they say greed is their downfall.

"He was nothing but a psychological liar and a total sociopath," said fraud victim William Neisokey.

William Neisokey is talking about the man who stole more than $90,000 from him in a ponzi scheme.

"My brother in law had been investing with him for 10 years and got his principle and interest back," said Neisokey. "He had a perfect track record and I saw no red flags."

The scam artist claimed he was investing in tax liens.

"In reality none of the money was invested in tax liens, the money went to pay off previous investors and his living expenses, your typical Ponzi scheme," said Mark Trachtenberg, US Postal Inspector.

Postal inspectors say the scam worked for more than a decade based on the con artist's good reputation in the community.

"He sounded like a really great guy and they trusted him," said Trachtenberg.

"When interest rates were 1% and this man offered us 16% interest- I saw dollar signs," Neisokey said.

William invested his entire 401-K and lost it all.

"I was absolutely devastated," said Neisokey. "I couldn't sleep nights, toss and turn, even sleeping pills didn't do any good. My blood pressure was at stroke level."

William admits he was lured in by the idea of quick money and he learned a lesson.

"Don't let greed overtake your common sense," said Neisokey.

Victims received a bogus email telling them the suspect in this case had died. In fact, he had fled to Thailand. Postal inspectors brought him back to the US where he was prosecuted.