A comely, red-haired leading lady with an open-faced, forceful manner, Marg Helgenberger began on the small screen as the feisty rookie police officer Siobhan Ryan on ABC's Irish-flavored daytime soap, "Ryan's Hope. " After some primetime guest spots, she landed a regular role supporting Margot Kidder and James Reid on the short-lived CBS series about two former con artists, "Shell Game" (1987). She fared better with her second series, winning an Emmy for the provocative Vietnam War drama, "China Beach" (1988-91). As K.C., a prostitute who attaches herself to a M.A.S.H. unit in Vietnam, Helgenberger brought forthright feminist insights to her brash, hard-bitten character. Though she would have a recurring role as George Clooney's love interest on NBC's popular medical drama "ER" in 1996, she had to wait for her return as a series regular until the Las Vegas-set "CSI: Crime Scene Investigation" (CBS, 2000- ). Cast as senior forensics investigator Catherine Willows, who tries to balance work and motherhood, the actress enjoyed a meaty role that earned her an Emmy nomination in its first season.