|Dr. Terror's House of Horrors (The Blood Suckers) (1965) [Bob Carroll]: Executed (off-screen), exact method unknown, after killing Jennifer Jayne. He is still alive at the end of his story, but at the end of the movie, it's revealed that all of the train passengers are already dead and that their stories weren't visions of the future but flashbacks to the past.
The Dirty Dozen (1967) [Vernon L. Pinkley]: Shot in the back by Nazi soldiers outside the chateau. (Thanks to Michael)
The Split (1968) [Dave Negli]: Killed in a struggle with Jim Brown in a steam room. (Thanks to Michael)
Start the Revolution Without Me (Two Times Two) (1970) [Charles Coupe/Pierre de Sisi]: Playing a dual role as two sets of twins in different time periods, the two 20th-century twins are both shot to death by Gene Wilder. (The fate of the 18th-century twins is never revealed, due to the deaths of all the would-be narrators.) (Played for comic effect.) (Thanks to Lawrence)
Don't Look Now (A Venezia...un decembre rosso shocking) (1973) [John Baxter]: Throat slashed by a dwarf (Adelina Poerio) whom he had mistaken for the ghost of his dead daughter. (Thanks to Scott and Michael)
Day of the Locust (1975) [Homer Simpson]: Possibly killed by a lynch mob after Donald kills a young boy (Jackie Earle Haley); we only see Donald being carried away screaming by the mob.
End of the Game (Der Richter und sein Henker; Deception; Getting Away with Murder; Murder on the Bridge) (1975) [Lt. Robert Schmied]: Killed (off-screen) before his first appearance in the film. (I haven't seen this movie myself, but the IMDB identifies his role as that of a corpse.)
1900 (Novecento) (1976) [Attila]: Commits suicide by shooting himself to escape from an angry mob of socialist peasants. (Thanks to Robert)
Invasion of the Body Snatchers (1978) [Matthew Bennell]: Replaced (off-screen) by an alien duplicate; we discover that he's been replaced when Veronica Cartwright approaches him at the end of the movie.
Eye of the Needle (1981) [Faber, a.k.a. 'The Needle']: Shot in the chest by Kate Nelligan as he tries to escape in a rowboat. (Thanks to Michael)
A Dry White Season (1989) [Ben du Toit]: Deliberately run over by a car driven by Jurgen Prochnow. (Thanks to Robert)
Buffy the Vampire Slayer (1992) [Merrick Jamison-Smythe]: Stabbed to death with a stake by Rutger Hauer. (Thanks to Robert)
Benefit of the Doubt (1993) [Frank]: Reportedly shot to death while he's trying to kill Amy Irving. (Thanks to Robert and Michael)
Younger and Younger (1993) [Jonathan Younger]: Killed (off-screen) in a motorcycle accident; we see him let go of the handlebars while riding with Lolita Davidovich's ghost, followed by an abrupt cut to Donald and Lolita sitting on a cloud in heaven.
Natural Enemy (1997) [Ted Robards]: Burned to death William McNamara pours gasoline down the garbage chute, after Donald discovers Tia Carrere's body in the dumpster. (Thanks to ND)
Shadow Conspiracy (1997) [Jacob Conrad]: Commits suicide by shooting himself after Charlie Sheen exposes the conspiracy. (Thanks to ND)
Fallen (1998) [Lt. Stanton]: Shot in the neck by the possessed John Goodman, as Donald is about to take Denzel Washington into custody. (Thanks to Stephen)
Virus (1999) [Captain Robert Everton]: After being turned into a cyborg, he is destroyed in an explosion after Jamie Lee Curtis fastens a grenade to his chest. (Thanks to ND)
Panic (2000) [Michael]: Shot in the chest by his son (William H. Macy) in Donald's living room.
Uprising (2001) [Adam Czerniakow]: Commits suicide. (Thanks to EaganChris)
Cold Mountain (2003) [Reverend Monroe]: Dies of natural causes while sitting at his lawn table; his body is shown afterwards when his daughter (Nicole Kidman) goes out to check on him after noticing he hadn't come in from the rain. (Thanks to Stephen)
The Italian Job (2003) [John Bridger]: Shot in the chest by Edward Norton. (Thanks to Robert and Tal)
'Salem's Lot (2004) [Richard Straker]: Bashed over the head with a blunt object by Dan Byrd; his body is shown again later on when Dan and the others find him hanging from the ceiling, where Rutger Hauer had place him. (Thanks to Michael and Ben)
An American Haunting (2005) [John Bell]: Dies of a terminal illness. (Thanks to ND and Nick)
Beerfest (2006) [Johann von Wolfhaus]: Accidentally disconnects his own life-support equipment while drunk (shown on a TV news report of his death); his body is shown afterwards during his funeral. (Played for comic effect.) (Thanks to ND)