This death bore little relation to the two that preceded it. The details of the killing are still confused, but even the story the cops are telling in their own defense can't explain why one of them had cause to pull his weapon. Giuliani's response was, first, to say that everybody needed to wait and see what had happened. Immediately, publicity hounds and anti-cop demagogues in the city jumped down Giuliani's throat for releasing juvenile records that are supposedly sealed. And the mayor has done just that.
People do act in conformity very often with their prior behavior.
The cops involved in the incident were having trouble subduing Dorismond. Somehow a gun was unholstered. Somehow the trigger was pulled. So three undercover cops with a quota to meet as part of a marijuana-sweep went after a guy who came out of a bar having had a beer after work. He was angered, and ended up dead.