I’m a conserative, not a libertarian, but I will concede them the argument that we don’t need every locality having militarized police armed to the teeth. However, many major cities are virtual war zones due to black criminals. And that is not the fault of the police. Libertarians do themselves no good when they try to snuggle up criminals in the name of seeking justice for both sides.
One thing that has started is the serving of warrants with swat teams. These are people suspected of committing a crime. In some cases they might be justified in using swat teams for this, but it seems to bite them in the butt when they get it wrong. Wrong address etc.