The story started with a pizza delivery.

It ended with an important lesson about fraud that I always relay to CEOs and business owners I work with. Always prosecute employees who commit fraud.

In my business as a turnaround authority I often deal with the consequences of fraud. I’ve spoken at seminars and on radio shows about fraud. There is a section on fraud in my upcoming book, “How Not to Hire a Guy Like Me: Lessons Learned from CEOs’ Mistakes.”

Last year fraud cost companies in the US more than a trillion dollars. It’s a topic worth discussing.

While this story told by a young man about a pizza delivery gone wrong deals with the theft of a small amount of money, it illustrates an important point about fraud that this young man recognized. If you don’t prosecute people who steal from you, they will steal from someone else.

The story was on a podcast from The Moth, a site dedicated to storytelling and was told by Tristan Jemerson, who at the time was a student also working a minimum wage job. He had his identity stolen and all the money drained from his bank account.

He thoroughly investigated the crime himself and discovered that a woman who took his credit card number when he ordered a pizza at Domino’s was the one who made all the charges on his account. Working with the police, he had her arrested and the bank reimbursed all his money.

Then he got a call from the CEO of Domino’s. He thanked Tristan for his help on the investigation, conveyed his apologies and asked Tristan what he could do for him. After considering the offer and rejecting the idea of a lifetime of free pizzas or a pizza named after him, Tristan said, “I don’t want this to happen to anyone else. I want you to pursue it to the furthest extent of the law. And I want every new Domino’s Pizza employee to hear this story and be told that if they mess with credit card numbers, they will go to jail.”

The CEO said he could do that. And Tristan received a personal thank-you letter from the CEO that included a check for all the money that was stolen, although Tristan had said the bank was reimbursing him, and $500 in Domino’s bucks.

What Tristan recognized that many business owners don’t, or choose to overlook, is that once someone commits fraud and is not prosecuted, they most certainly will do it again.

I have dozens of examples of controllers, CFOs, warehouse managers and payroll clerks who were never prosecuted when they were originally caught stealing, and nearly every one of them stole again, eventually.

I know, because I’m the one who caught them and then finally had them prosecuted.

In one case a bookkeeper at a church stole millions of dollars from the church. She had done the same thing at a previous church in another state, but because that church chose not to prosecute, she just relocated and started stealing again.

If you experience fraud at your company and are tempted to let it slide, I hope you’ll remember the lesson of Tristan and the pizza delivery. Prosecute anyone who steals from you.