Crime History: California man kills 7 co-workers

On this day, Feb. 16, in 1988, a man obsessed with a co-worker kills seven employees of a high tech company in Sunnyvale, Calif., in a case that became a national emblem of workplace violence.

For four years, Richard Farley stalked ESL Inc. co-worker Laurie Black, writing 200 letters to her, calling her office every few hours and showing up at her aerobics class. He was able to obtain information from her personnel file.