Mark Harmon is an American actor who has been starring in U.S. television programs and films since the 1970s. Currently with a lead role in the series NCIS, Harmon also played notable roles in St. Elsewhere, Flamingo Road and Chicago Hope. His family is also involved in show business: he is married to actress Pam Dawber, was the brother-in-law of the late singer Ricky Nelson, and is uncle to singers Matthew and Gunnar Nelson of the pop duo Nelson and actress Tracy Nelson.Photo credit: Jerry Avenaim