Special-education teacher assistant Jennifer Amerson stopped working for the Charleston County School District in June 2010, but the district deposited checks into her bank account from August 2010 through March 2012.

The school district sent her $34,188 that she had not earned, and when officials realized their mistake, they sued Amerson to get the money back.

"There were miscommunications," said John Emerson, the district's attorney. "There were weaknesses in personnel and in the system that we're working on. ... Errors were made, and supervisors should have noticed that someone was on a payroll who wasn't present."

Amerson's situation appears to be the largest overpayment to a terminated employee in recent history, but it's not the only one. The district accidentally paid 35 employees a total of about $65,000 during the 2012-13 school year, and that's not counting Amerson.

The overpayments happened for different reasons, and they represent 0.4 percent of the roughly 8,000 tax forms the district issued for that year. Anything more than "zero" isn't good, but these numbers are good, said Mike Bobby, the district's chief of finance and operations.

"We are actively involved in recovering every penny," he said.

The management letter of the district's audit recommended process and procedural changes for its payroll department, and officials say those are happening.

The district gives schools and departments lists of the employees who are supposed to work there, and supervisors are supposed to review those for accuracy, Bobby said. That had been done in the past, but it's happening now on a monthly basis, he said.

The district also is working toward an automated system in which hourly employees would have to manually input their time. If employees aren't present to do that, then they wouldn't be paid, Bobby said. He hopes to have that in place by the 2014-15 school year.

Neither of those changes were in response to the Amerson case.

"We think we do a good job, but we're working on doing a better job when we know there are issues we can improve upon," Bobby said. "That's what we take away."

Officials described the Amerson case as unique, and the type of job she had and its funding source added to her situation's complexity.

No one answered the door at the North Charleston address where district officials stated in legal filings that Amerson lived. The Post and Courier left a note in the mailbox at that address telling Amerson about this story and asking her to speak with a reporter.

A woman left a voice message on a reporter's phone saying someone apparently knocked on her door and that she didn't want to speak with anyone.

"I just want to keep my life confidential," she said in the message. "Please don't come and knock on my door anymore."

Amerson held multiple positions while working for the school district. Most recently, she had been a special-education assistant for a specific student at Goodwin Elementary. She was paid out of federal Title 1 money, and that money is a different funding stream than that of most traditional classroom teachers.

Her assigned child transferred to C.C. Blaney Elementary for the 2010-11 school year, so her position moved, too. Emerson, the district's attorney, said Amerson never showed up at Blaney, but she also never submitted a formal resignation letter.

Those factors, as well as problems with personnel who process paperwork and no longer work for the district, created a "perfect storm" for the overpayment, Emerson said. No one person was at fault.

"The facts are that it happened, and this situation is very unusual," Bobby said. "It's now being corrected and we're moving on. Anytime there's a situation where something doesn't work the way we intended, we try to examine what happened and do what we can to change the system."

The district won its legal case against Amerson, who has repaid at least $3,535 of the $34,188. She still owes the district money, and officials are in the process of collecting those funds.

"She has not been cooperative," Emerson said.

The district asks anyone who has been overpaid to repay the money, but that typically doesn't involve litigation.

Todd Garrett, a county school board member who chairs its audit and finance committee, said he would like the committee to discuss this issue with the administration. He wasn't aware of the overpayments, and that's something that should be reported to the board, he said.

"It's a waste of taxpayers' dollars," he said.