Washington (CNN) Former President Barack Obama reported for jury duty in Chicago on Wednesday but was ultimately dismissed from the pool.

He was assigned to a panel that was not called, Chief Judge Tim Evans, who presides in Cook County, said at a news conference held after Obama departed. He added that the 44th president was gracious to others who were there to fulfill their civic duty.

"The public allowed him to come in and to do his duty. I thought, for example, he would be reticent about greeting them. He came in and greeted the prospective jurors on both side of the panels. We had about 220 people here. He took time to greet people on both sides," Evans said.

Once potential jurors saw that Obama was approachable, Evans said some decided to test their boundaries.

"He discovered that some knew they might have a chance to meet him and they brought books for him to sign," the judge told reporters. "I saw him pause for a moment and I thought his Secret Service panel may not permit him to do that, but he said that he wanted to sign their books and he did sign."