Marg Helgenberger. Actress: CSI: Crime Scene Investigation. Marg Helgenberger is an established dramatic actress whose prominence has been steadily increasing. Her work has been noted on stage, film and TV. Most of her career has been spent in dramatic roles on television, but she has also had a noteworthy presence in feature films. Helgenberger earned a degree in drama at Northwestern University. A talent scout recruited her from there to work...