Israeli Prime Minister Shimon Peres defended the embattled head of the Shin Bet internal security agency and accused U.S. news organizations of conducting a "trial by media." Israeli Atty. Gen. Yitzhak Zamir has accused the Shin Bet chief, Avraham Shalom, of attempting to obstruct justice in a probe of the apparent murder of two Arab terrorists by their Israeli interrogators after a bus hijacking two years ago. Zamir has complained of official pressure to drop the case. Peres denied this and contended that an investigation would jeopardize national security. After his Parliament speech, Peres defeated four no-confidence motions over his handling of the affair.