In town to plug his new book, former Vice President Dick Cheney had some careful criticism Monday about the U.S. attorney in Chicago, Patrick Fitzgerald.

Fitzgerald served as special prosecutor investigating a leak during the Bush Administration. He ended up charging Cheney’s chief of staff, Scooter Libby, with perjury and obstruction of justice.

At the Union League Club of Chicago, Cheney was asked if he had anything to say to Fitzgerald, whose offices were just a block away. The vice president paused for nine seconds.

“I obviously had some fundamental disagreements with him at one point in the past,” Cheney said.

Cheney called Scooter Libby a “very good man” who served his country well.

“For his trouble, he ended up the target of a particular prosecution,” Cheney said. “He did not deserve what happened to him.”

Also during his hour-long appearance in front of more than 400 people, Cheney defended interrogation techniques used on terrorism suspects. And he declined to say whether he thought President George H.W. Bush or George W. Bush was the better president.