For years, Decatur police knew Nacina Walker to be the helpful employee in Walmart’s cash department who would sometimes help them investigate thefts at the store.

“She would be the one that would come in and help us and go, ‘Oh, you need to punch in this number, do this,’ or ‘Let me find it for you,'” said Detective Gerald Wright.

You can imagine Wright’s surprise when Walker herself ended up being the focus of the biggest theft case he’s ever handled.

Walker, 50, was arrested Tuesday and charged with theft of property of more than $200,000. Police said between January 2013 and October 2014, Walker would create fake returns while working at Walmart, then would pocket the refunds.

In total, police believe she stole nearly $240,000.

The refunds started small, then grew, Wright explained. “$8,000 a day. I mean, $8,000 in a month is a lot of money, but in one day?”

The detective said Walker told him she did it to help pay bills. An affidavit shows Walker had worked at Walmart since 1982.

Police allege that Nacina Walker created bogus returns to pilfer cash from the Walmart store in Decatur.

According to the asset protection manager’s report documented in her arrest warrant, Walker was interviewed by his department on Oct. 15, 2014 and admitted to several thefts from the cash office. In her statement, Walker said she was on a salary cap and she needed the money for medical bills, her husband’s business, and because she is caring for her elderly parents.

Walker said in her statement she was unsure when she began stealing from Walmart, but it started with small amounts, taking 50 here and there. She said once it became clear no one was noticing the smaller amounts, she began to steal more and more, eventually taking as much as $8,000 a day.

She said it was as if she couldn’t stop and it “snowballed,” the warrant said.

But the retail giant did catch on, fired her, and passed the case to police. A spokesman at the Walmart corporate office in Arkansas said he could not say where this case measures up as far as the most money an employee has been accused of embezzling.

The manager of the Decatur Walmart declined to comment, but employees there said they were shocked at the accusations, mentioning that Walker had worked there since she was in high school.

Walker’s next-door neighbor, Leonard Prohs, was similarly astounded by what police say Walker did.

“I don’t have a whole lot of sympathy for these folks to steal that kind of money,” he said.

Walker was released from the Wise County jail Tuesday after posting a $30,000 bond, the sheriff’s office said.

We tracked her down Wednesday at her new job, where Walker told us her attorney had advised her not to speak. Her new boss told us he’s known her and her family for a long time, and he trusts her.

But if convicted, Detective Wright said Walker faces “anywhere from five to 99 [years] in prison,” adding that the crime is a first-degree felony.