FIRST OFF . . .

Entertainers who are scheduled to appear at a benefit concert for Indian activist Leonard Peltier tonight in Costa Mesa have been criticized by Richard T. Bretzing, head of the FBI’s Los Angeles office, for taking part in what the FBI agent termed an “utterly revolting” cause. Robin Williams, Kris Kristofferson, Willie Nelson and Joni Mitchell are among those scheduled to perform at the benefit, taking place at the Pacific Amphitheatre tonight. Concert organizer Peter Coyote defended the idea behind the benefit. “We’re not saying (Peltier is) innocent and that he should be released, we’re just saying he should get a new trial,” said actor Coyote, who added that all the participants asked for background information on the Peltier case before agreeing to the show. Peltier, a founder of the American Indian Movement, was convicted in 1977 of first-degree murder for the 1975 slayings of two FBI agents in a shoot-out at a South Dakota Indian reservation. An Indian was also killed.