Thomas Mark Harmon (born Sept. 2, 1951) is an American actor. At the University of California he was the starting quarterback for the UCLA Bruins football team in 1972 & 1973. He has appeared in a variety of TV, film & stage roles. His character 'Dr. Robert Caldwell' (1983-86) in the NBC hit series St. Elsewhere was one of the first TV characters to contract HIV/AIDS. In January 1986, he was named People magazine's Sexiest Man Aive. Harmon & his wife are outspoken activists of gun control.