William Kaan was angry after he installed two air conditioning units in a home and then discovered the credit cards used to pay for the work were no good.
"We felt pretty bad...we lost $6,000," said Kaan.
Postal inspectors told Kaan he had gotten caught up in an identity theft scam.
"It began with the perpetrator ordering cards, credit cards in other people's names sent to a specific address," explained US Postal Inspector Andre Brown.
The suspect then used the fraudulent cards to go on a shopping spree. There were about 90 victims with $2.5 million in losses.
Kaan was one of those victims until he turned the tables on the suspect. The small business owner went "undercover" with postal inspectors to catch the fraudster in the act.
"We made an estimate for a new air conditioning unit; He didn't want to give me his card. He said he'd call it in. When we got back here, we called in a card it was bad," explained Kaan. "I told him on the phone, that card is no good; he said wait a minute I got another card. He gave us another number, we ran that and it was a bad card too."
Postal inspectors quickly arrested the suspect.
"Don't let it go, don't think that your money is lost - it might be still there - but you still want to put the fellow where he belongs if he's doing it to a lot of people. Take care of your own business," said Kaan.
To insure you're not a victim of identity theft, don't forget to check your credit report. Every year you're entitled to one free credit report from each of the three credit bureaus - that's three free reports a year. The Northeast Better Business Bureau recommends using the website annualcreditreport.com.