{I}n court documents filed late Tuesday, Schock's attorneys say the government went too far when it transformed the staffer into an informant and required him to wear a wire to secretly record conversations-- in addition to providing more than 10,000 pages of legislative emails, staff rosters, employee records and confidential documents from Schock's district office the defense considers to be stolen property. The informant rummaged through the desk of Schock's chief of staff and taped conversations with other staffers, the attorneys said.

...Schock's attorneys say the FBI used the informant to get around restrictions on what a federal agent would not have a right to search and seize. The documents suggest Schock's attorneys will move to have the case dismissed by citing, among other things, alleged illegal searches and prosecutorial misconduct.

Using an informant is not uncommon in public corruption cases, but they tread a fine constitutional line, said Jeff Cramer, a former federal prosecutor who is not involved in the Schock case.

"The problems may occur when or if this informant crosses the line starts gathering information at the request of law enforcement that he or she should not be looking for," he said. "When you add a sitting congressman to the calculus it becomes even more fraught with peril."