Jerry Whitworth's chief defense lawyer, James Larson, is no stranger to defending underdogs.

A graduate of Stanford University and UCLA law school, Larson said he was active in "the movement" during the 1960s and ended up representing "draft resisters, black liberation groups, prisoners and alleged lefties."

The most celebrated was Wendy Yoshimura, a Symbionese Liberation Army member captured with heiress Patricia Hearst in San Francisco in 1975. Yoshimura was convicted of illegal possession of weapons and explosives in connection with terrorist activity in Berkeley, Calif., in the early 1970s.

"Philosophically and politically I am always concerned with the abuse of power by the government, and I think there are a lot of interesting intellectual and moral issues involved in criminal law," Larson, 42, said in a recent interview.

The Whitworth case is Larson's first espionage trial, and "it's definitely the most challenging of all," he said. "Particularly in this case, you've got the full weight and power of the government coming down on an individual, and the drama basically takes place on the front page of the newspaper. It really calls upon every resource that you've got to defend him."

Larson has been working full time on the Whitworth case for about six months. His cocounsel is Tony Tamburello, who has simultaneously been preparing to handle the retrial of Larry Layton, former People's Temple member charged with conspiracy in the 1978 slaying of a California Democratic congressman Leo J. Ryan at Jonestown, Guyana.

Tamburello's fees are being paid by the government because -- although the federal death penalty for spying has been invalidated -- espionage under the law is still technically a capital crime that entitles a defendant to a second lawyer.

"I'm certainly looking forward to a resolution of the case," Larson said. "I think it's going to be a very interesting trial."