As a subject matter expert on comic book lore and superhero narratives, I can provide a detailed answer to your question. In "The Amazing Spider-Man," Uncle Ben's death is a pivotal moment in the storyline.
Uncle Ben is killed by a burglar who earlier had broken into the house of Peter Parker's Aunt May and Uncle Ben.
Peter had the opportunity to stop the burglar but chose not to get involved, believing it was not his responsibility. Tragically, this same burglar later kills Uncle Ben, leading to Peter's realization that with great power comes great responsibility, which becomes the guiding principle of Spider-Man.

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In Spider-Man 3, it is revealed in a retcon that the "Carjacker" (now identified as "Dennis Carradine") is not responsible for Ben Parker's death as assumed. The true killer is Carradine's partner, Flint Marko (who later becomes the Sandman); there were two witnesses who saw the whole scene.read more >>