Shane Owens patrolled the streets of Dallas for almost nine years.

Most of it was spent in in downtown.

So when he quit last month, he was expecting a final pay check of a couple hundred dollars. Instead, he got a bill from the city saying he owed them $999.08. The letter claimed the city overpaid him for a four-month period two-and-half-years ago.

“It was a slap in the face to be honest,” he said.

The city acknowledges making a mistake.

They say Owens should've stopped getting patrol differential pay in September 2014 after his shift changed. But it didn’t stop because the police department didn’t send a notification to the city’s payroll department until January. A letter should've gone out notifying him that he had been overpaid but didn’t.

“We didn’t handle it right and we’re going to look at our process and see where the disconnect was,” said Molly Carroll. a director with human resources. “But, we still have to collect the money.”

City officials say it's common practice to audit employee payroll. Sometimes that means the employee owes money and other times it means that the city owes them money.

“I think it's completely ridiculous,” said Mike Mata, president of the Dallas Police Association. “The city, they're the ones who messed up. They're the ones who made the error.”

Something similar happened to Mata several years ago.

He says the city discovered that he had been overpaid a small amount for two years. It added up to more than $4,000. He paid the money back in installments.

“It's not the officers responsibility really to look at every dime,” he said. “We’re paid hourly so our check fluctuates quite a bit with overtime.”

Owens said the city did one audit last year at his request and found they owed him a small amount of money. A second audit found he owed them a small amount, he said.

“You would think if there’s an issue through the first two audits they would've found it,” he said.

Owens doesn't even have a way to determine if the city's calculations are correct.

He said the check will not be in the mail. Instead, he said he may just send the city a bill for the years they didn't pay him enough for putting his life on the line.