ATHENS, Greece (AP) — A telephone operator arrested for being a leader of Greece's deadly November 17 terrorist group admitted taking part in the 1975 killing of a CIA official and said the triggerman already is in police custody, judicial sources said Friday. The surprise confession by alleged second-in-command Pavlos Serifis added important details about the ambush killing of CIA station chief Richard Welch outside a Christmas party — a killing that launched a 27-year string of assassinations, bombings and robberies by the once-untouchable group. Serifis also admitted participating in the 1980 slayings of two Greek policemen and said the...