In which episode is Secret Service agent Simon Donovan killed?

Secret Service agent Simon Donovan is killed in the episode “Posse Comitatus.”

The episode is the third-season finale of The West Wing and places Simon’s death within a tense night involving presidential diplomacy, political violence, and personal loss. Simon, played by Mark Harmon, is assigned to protect White House Press Secretary C. J. Cregg and has developed a close relationship with her.

Near the episode’s end, Simon stops at a convenience store while off duty. He encounters an armed robbery and intervenes, but is shot and killed. The suddenness of the event makes it especially memorable: Simon is not killed during a formal presidential protection operation or in a foreign-policy crisis.

“Posse Comitatus” originally aired in 2003 and is often remembered alongside “Noël,” the episode that introduced Simon’s relationship with C. J. The other choices are also notable West Wing episodes, but they concern different storylines: “Two Cathedrals” centers on President Bartlet’s crisis of faith, while “In Excelsis Deo” focuses heavily on Toby Ziegler.