PEORIA - The Democrat running against Republican Aaron Schock for an open congressional seat has asked prosecutors to investigate documents that Schock backdated while helping his parents set up tax shelters. | Interactive Video: Create your own 11th Congressional District debate

A spokesman for Democrat Colleen Callahan said Wednesday that Peoria County State's Attorney Kevin Lyons has agreed to investigate, though Lyons' office declined to answer questions on the subject.

A notary who falsified dates on a document could be guilty of a misdemeanor under Illinois law.

The Associated Press reported Tuesday that Schock's father testified in federal court that his son used false dates in notarizing the documents in 2001.

"We think there are a lot of questions, and Aaron needs to provide some answers," Callahan campaign manager Terry Towery said. "It's my understanding that (Lyons) agreed to try to gather the facts."

A woman who answered the telephone at Lyons' office, however, would not address Callahan's request for an investigation.

"They're not talking today, I'm sorry," she said before hanging up.

Schock, a 27-year-old Republican from Peoria, hasn't disputed his father's testimony. He said voters should choose their candidate based on key issues rather than something he says he scarcely recalls.

"It's an attempt by my political opponents in the final weeks to dig up any kind of dirt to use against me," he told the Peoria Journal-Star. "I'm sure there will be more to come in the weeks ahead, and the voters will have to decide based on my positions on the issues and public service record on who best is able to represent them in Congress."

Schock and Callahan are running for the 18th District seat held by Republican Rep. Ray LaHood, who is retiring. Schock has been favored to win the reliably Republican central Illinois district, and would become the youngest member of Congress.

Schock has said he became a notary as a teenager because he worked at a gravel company that needed documents notarized.

His father, Richard Schock, was a witness in the trial of the three people accused of tax fraud. He said he and his wife put money and property into a variety of corporations and a charitable trust beginning Jan. 1, 2000, as directed by two of the defendants, Kenton Tylman and Debra Hills.

But Tylman and Hills, Richard Schock said, did not provide some documents for them to sign until the next spring. He testified that he and his wife signed the documents and their son notarized them with the earlier date because that's when the tax shelters were established.

Prosecutors did not suggest Richard Schock benefited financially from using the false date.

According to the Illinois secretary of state's office, which licenses notaries, using an incorrect date would be official misconduct. Knowingly committing official misconduct is a Class A misdemeanor, while doing it through recklessness is a Class B misdemeanor.