WASHINGTON -- Some of Illinois Rep. Aaron Schock's current and previous employees will appear before a federal grand jury next month to answer questions about their old boss. When they do, they'll likely face a prosecutor with a tough, meticulous reputation.
Timothy Bass, a 20-year veteran prosecutor who's involved in the investigation, is known for combing through every detail of his cases. He's prosecuted drug and gun crimes, money laundering, tax evasion, child pornography, exploitation and corruption cases.
The government has been looking into Schock's House office expenses, his re-election campaign spending and his relationships with long-time political donors. The Justice Department issued subpoenas as part of this investigation.
The choice to investigate Schock in central Illinois - rather than in Washington, home to his Capitol Hill office - could signify the probe reaches beyond the potential misuse of his congressional office and into his congressional district activities or hometown financial contributors.
Schock, a 33-year-old Republican from Peoria, plans to step down Tuesday. His departure follows months of press reports into his office and political expenses, including improper mileage reimbursements and trips on his donors' aircraft, as well as business deals with those contributors.
New details offer a rare look inside the secretive grand jury process, which takes place behind closed doors. That makes it difficult to understand how prosecutors may be building a criminal case against the congressman, what evidence they're compiling and whether anyone else in his sphere might be in trouble.
"Tim Bass will be very deliberate, very meticulous and very focused," defense attorney Jon Gray Noll said of the 51-year-old assistant U.S. attorney in Springfield, Illinois, whom Noll says he and others call "Badass Tim Bass." Bass was behind the creation of the Illinois Central District's Public Corruption Task Force formed in 2007.
"If I were sitting where Mr. Schock is, I would not want this gentleman on the other side," said Noll, who's not representing Schock.
Since 2013, Bass' task force has resulted in the convictions of 13 people related to $16 million in grant and contract-fraud schemes, his office said. Bass, who declined an interview, is known for being incredibly prepared, said another defense attorney who has gone up against him.
Illinois is well known for federal prosecutions against former governors, crime bosses and municipal officials. They include the trial and conviction of former Democratic Gov. Rod Blagojevich in the Justice Department's northern Illinois district.
Federal investigators who questioned likely grand jury witnesses indicated during their questioning that the probe will go beyond his House office expenses. They're interested in how his money was spent and his business relationships with his donors, according to a person familiar with the probe but who was not authorized to speak publicly.
The grand jury in this case could indict Schock or not, and they also could target other possible co-conspirators. But individuals can also avoid a grand jury by pleading guilty or otherwise cooperating before they are even indicted.
U.S. investigations into elected officials can cover a broad swath of allegations, such as whether a lawmaker traded favors for gifts or bribes, misused campaign funds or lied on disclosure reports. Those cases can be complicated by reluctant or unreliable witnesses, not to mention getting past certain constitutional protections afforded to members of Congress.
Schock's attorney is William McGinley, who's represented political figures - including New York Rep. Michael Grimm - and others in cases involving congressional ethics investigations, campaign finance law and grand jury proceedings. McGinley and his colleagues at the Jones Day law firm have represented Schock since February.
A spokesman for Schock declined to comment.
Schock, a one-time rising star of the Republican party, announced his resignation after a weeks-long cascade of revelations about his business deals and lavish spending on everything from overseas travel to office decor in the style of the TV show "Downton Abbey." Congressional ethics investigators were probing Schock's conduct in the days before his announcement.
The questions raised have included Associated Press investigations into Schock's real estate transactions, air travel and entertainment expenses, including some events that Schock documented in photographs on his Instagram account. Reports by Politico and other news organizations also singled out Schock's unusually high, personal reimbursements for auto mileage.
Shock has reimbursed the government for tens of thousands of dollars in expenses, including more than $1,200 in travel expenses for attending a Chicago Bears football game last November.