> there was no crime wave in the early 2000s when the militarization of police began

I would argue we started the militarization of police in the 1970s-1980s when NYC was a festering hotbed of crime and when Miami drug dealers were shooting automatic weapons during turf wars (which was when we started Civil Asset Forfeiture... which allowed police/prosecutors to essentially steal assets from civilians without a criminal conviction).

We gave surplus DoD weapons to police for cheap after 9/11 and judges started rubber-stamping no-knock warrants around 2001, but I don't think that was the only inflection point.