Almanac: The Unabomber

Twenty years ago today, the FBI arrested Theodore Kaczynski, the suspected Unabomber at his cabin in rural Montana. For years, the only clue to the mysterious series of bombings across the country that killed three people and wounded 23 others was a single sketch of a shadowy hooded figure - until his manifesto was printed by the Washington Post, and Ted Kaczynski's brother grew suspicious. Charles Osgood reports.