William Petersen has a distinguished background in film, theater, and television. His television credits include the films Long Gone, The Rat Pack, The Kennedys of Massachusetts, which won a Golden Globe Award, and The Beast. He also serves as executive producer of CSI: Crime Scene Investigation and was nominated in 2003 for a Golden Globe Award for his portrayal of lead investigator Gil Grissom.
His feature film credits include To Live and Die in L.A., Manhunter, Cousins, Young Guns II, Fear, Hard Promises, which he also produced, and The Contender.
Peterson made his Broadway debut in a revival of Tennessee Williams' The Night of The Iguana. In 1979 he founded the 'Remains Theater Ensemble' in Chicago with a group of fellow actors. He has appeared in a number of regional stage productions including A Streetcar Named Desire, The Time of Your Life, Glengarry Glen Ross, Fool for Love, and Speed-the-Plow.
Petersen was born in Evanston, Illinois, and first discovered acting while on a football scholarship at Idaho State University.