WASHINGTON —  One of the nation's most familiar "prosecutors" showed in Scooter Libby's camp in court Thursday.

But it was a "prosecutor" who only plays one on TV.

Joining Libby's public-relations representative, Barbara Comstock, in the public gallery was former Tennessee Republican Sen. Fred Thompson, who plays a New York City prosecutor on the NBC series "Law and Order." He came to listen while another NBC star, Washington bureau chief Tim Russert was cross examined by defense attorney Theodore Wells.

At one point, Libby's wife, Harriet Grant, went back and sat beside Thompson. They hugged, laughed and chatted for a few minutes before she returned to her seat in the front row.

Asked why he came Thompson said, "I'm a friend of Scooter Libby and his family."

During a late-morning break, Libby and Thompson shook hands in the hallway and went into a private conference room to chat. Thompson did not return for the conclusion of the morning session.

The former senator is on the steering committee of the Scooter Libby Legal Defense Fund Trust, an organization that set out to raise more than $5 million to help finance Libby's defense.

Thompson, who declined to answer more questions Thursday, hosted a fundraiser at his northern Virginia home last May to raise money for Libby's defense fund.