In Spectacular Spider-Man 221 (part of the Clone Saga, covered here), Kaine killed Doctor Octopus. And despite the fact that there are always major threats to lives and property in and around NYC, Peter Parker decides to prioritize capturing Ock’s killer.
After presiding over the funeral, Elias Hargrove–Otto’s closest living relative–reassembles the Sinister Six to try to find and take Octavius’ arms.
That’s the basic plot. From there, Kaine decides to kill the other Sinister Sixers (he fails), Ben Reilly does most of the work stopping him, and the arms are returned to government custody.