Eight years ago, Illinois Rep. Tammy Duckworth used a state-owned vehicle to drive to a campaign event, violating a state law that prohibits government employees from campaigning using taxpayer funds.

At the time, Duckworth was a state employee, the director of the Illinois Department of Veterans Affairs. She had scheduled a day off from her job in order to attend the campaign event, which was being held for then-congressional candidate Dan Seals.

"The state is very clear [so] we are very, very careful about taking personal leave, personal time, to come and do these types of things," Duckworth said, according to the Chicago Tribune. "I am here as a private person, and I took time off from work today to be here."

But as careful as Duckworth was to take time off from her job to campaign for Seals, she wasn't careful enough to avoid using a state-owned Dodge van to attend the event. This violated a separate law that prohibited state property or resources from being used for politicking.

At some point during the campaign event, the vehicle was moved out of sight of the building where the event was being held — and out of sight of where reporters gathered to cover her endorsement of Seals. Later that day, a Veterans Affairs spokeswoman admitted that Duckworth misused the vehicle for political purposes.

"She will reimburse the state for the use of the state vehicle, and will not make this mistake again," said spokeswoman Jessica Woodward.

But there is no record of Duckworth ever reimbursing taxpayers for the misused vehicle. Duckworth is now running for U.S. senator in Illinois.

In the spring of 2015, the National Republican Senatorial Committee sent a series of Freedom of Information Act requests to various Illinois state agencies to find out whether Duckworth ever repaid taxpayers. In March 2015, they sent a request to the Illinois Department of Central Management Services for records of Duckworth "recompensing the state as promised for personally misusing state vehicles" and included a reference to the Chicago Tribune article cited earlier in this post.

In April 2015, the NRSC sent a request to the Illinois Office of the Comptroller and the Illinois Department of Veterans Affairs for the same.

CMS could not locate "any records responsive to this part of your request." The comptroller said it did "not possess anything responsive to your request" and directed the NRSC to contact the IDVA. The IDVA could not locate "any documents responsive to your request."

The closest thing to evidence of Duckworth repaying taxpayers is a mention in a 2012 Daily Herald article claiming the former IDVA director "apologized for the mistake and reimbursed the state for use of the vehicle." The article does not mention what evidence there is to suggest Duckworth paid back the state, and appears to have just assumed based on the congresswoman's claim that she would pay the money back four years earlier.

It is entirely possible that Duckworth paid back the money. Her campaign told the Washington Examiner that Duckworth may have owed as little as $17 for misusing the vehicle, based on the miles traveled (33) and the gas-per-mile paid for by the state. This could be true, or the amount could be higher if Duckworth brought any staff with her or was driven by someone who did not also take time off from state work to be there.

And if it was only $17, why not pay it back? It's such a small amount, why avoid it?

Then again, just because three departments found no records of reimbursement doesn't mean it didn't happen. Illinois isn't the best when it comes to FOIA requests. State agencies routinely stonewall such requests, prompting Gov. Bruce Rauner to sign legislation that would increase fines for agencies that refuse court orders to turn over information. Of course, that legislation was in response to a young woman who died of a gunshot wound and her father's fight to obtain police records about the incident, not state agencies being unable to find records of whether a state employee reimbursed taxpayers.

Still, the law received support in part due to the unresponsiveness of the state in general to FOIA requests. Rauner himself has been criticized for allegedly concealing information from FOIA requests.

It still seems odd that the NRSC received a response from the state agencies (they weren't ignored or stonewalled) but that those state agencies couldn't find evidence Duckworth repaid taxpayers. Then again, proving a small payment one made eight years ago could be difficult for anyone. Duckworth may be able to prove the payment by checking her bank records, but as of right now, there is no concrete evidence she made the payment except for the campaign's say-so.

The Duckworth campaign did not provide a comment prior to press time.

Ashe Schow is a commentary writer for the Washington Examiner.