Movies:
* To Live and Die in L.A. (1985)
* Manhunter (1986)
* The Silence of the Lambs (1991)
* Fear and Loathing in Las Vegas (1998)
* The Contender (2000)
* The Salton Sea (2002)
* CSI: Miami (2002) - *Brief appearance as Gil Grissom*
* The Good Shepherd (2006)
* The Yellow Handkerchief (2008)
* The Lake House (2006)
* The Woman in the Window (2021)
Television:
* The Fall Guy (1981-1986) - *Recurring role*
* CSI: Crime Scene Investigation (2000-2015) - *Lead role as Gil Grissom*
* Manhunt: Unabomber (2017) - *Lead role as FBI Agent Jim Fitzgerald*
* Murder in the First (2014-2016) - *Lead role as Terry English*
Other:
* The Pentagon Papers (1971) - *TV movie*
* The Killing of Randy Webster (1979) - *TV movie*
* The Anderson Tapes (1971) - *TV movie*
* The Virginian (1963) - *TV series, 1 episode*
Note: This is not an exhaustive list but includes some of William Petersen's most notable projects. You can find more information about his complete filmography on websites like IMDb.