With audience interest high in the recent conflict between the Hezbollah and Israel and the arrest of a man in the JonBenet Ramsey murder case, ABC's Nightline has topped CBS's Late Show with David Letterman for the third consecutive week to place second behind the Tonight show with Jay Leno. According to Nielsen Research, Leno averaged 4.52 million viewers last week, well ahead of Nightline's 3.71 million. Letterman was close behind with 3.56 million. Although it was feared that Nightline's audience would fall off steeply following The Departure of Ted Koppel last fall, the show has actually seen a 17-percent increase in its audience.