It will turn out that the burgular was in the employ of Doctor Octopus, all part of his long range plan to marry May.
But Ben wasn't really dead. The government used him in a top-secret Super-Veterans programme. His shattered kidneys were replaced with a new, experimental polymer designed to flush his system at superhuman speed, and his memory was wiped.
He is kept in cryogenic suspension, only awoken when the government needs to call on his unique services once a decade or so.
Then, in his new identity of Gerry Hattrick (Codename: The Golden Fountain) he is placed in Old Folks homes deemed to harbour subversive pensioners and put those people quietly out of the way.
Unfortunately, seeing so many sets of false teeth on bedside tables reminds him of the woman he loved, and slowly his suppressed memories begin to break through. Fearing the shock of his return would be too much for Aunt May's time-tattered ticker to bear, he decides not to reveal himself, but donning a special pair of adamantium/vibranium incontinence pants, he watches over her from the shadows.
However, reports of an old perv in the area bring him into conflict with the police, whom he easily defeats, and eventually with Spider-Man, who discovers his true identity. To Peter's horror, his beloved uncle decides to continue his work as an assassin of the nearly-dead-anyway.
How can Peter defeat an enemy he loves? How can he fight a foe with bones so brittle that one punch would shatter them beyond repair? How can he battle a man who cannot possibly outrun him? See the thrilling answers in:
Spider-Man: One More Day If He's Lucky And Doesn't Move Too Fast.