Diann Cattani's embezzlement started off as an innocent mistake and then quickly got out of control.
NEW YORK (CNNMoney) -- My first indiscretion was very accidental.
I had been brought in as a project manager for a boutique human resources firm in Atlanta in the late 80s and early 90s.
It was a startup, so the owners relied on me to take over the company's business functions. I automated the bookkeeping systems, contracted with all of the vendors and basically did everything that it took to set up the company's infrastructure. I never established systems with the plan to steal from them, but the fact that I implemented everything made things a lot easier.
A few years later, my family and I were traveling for the holidays, and the travel agent inadvertently charged my personal travel onto my corporate American Express account. I noticed it and planned to reimburse the company as soon as I got back.
That never happened.
My stealing just got worse. I applied more personal expenses to the company, justified false invoices, and created dummy vendors in the system and then wrote checks to myself.
Research shows that for every white-collar crime there are always three elements involved. It's called the fraud triangle, and it consists of opportunity, pressure and rationalization.
Opportunity was always there for me. I didn't have a lot of financial pressures, but I definitely crossed over into rationalization. I was living this amazing life -- traveling around the world -- and I didn't want to deprive myself.
Over the next three-and-a-half to four years, I stole almost $500,000.
I think that there is just as much fraud and theft going on today, and probably more -- but now it's out of necessity. People are desperate, and it could mean the difference between making a mortgage payment or not.
I speak at conferences across the country and, although I don't know if there are ways that small business owners can completely prevent fraud, there are certainly some deterrents.
First, honesty and integrity have to be core competencies that are practiced by everyone, especially the owners and senior executives. If employees know that execs are using company funds for personal reasons, it will affect the entire culture.
Also, small business owners have to trust employees, but also verify. Have bank statements sent to your home, and double check everything against source documents like cancelled checks. Protect people from themselves.
Most importantly, always be aware and on guard. When I turned myself in, my bosses were completely surprised; they really had no idea.
I was charged with felony mail fraud, and I served 15 months of an 18-month sentence in a Florida prison. When you get to jail, you think that's the end of the world. But once you get out, you realize that was the easy part.
As a felon, I can't hold a professional license or even sign a lease on an apartment. And the hardest part is finding a job.
The company that I was most recently working for got bought out, and I just received my two-week notice. It's scary, but I'm actually thinking about going into business for myself. It's really my best option at this point.
So am I scared of being stolen from? Absolutely not. I lived that life, and I know exactly what to look for. 
