That is why I’m arguing for not celebrating this way of handling problems. Executions, even official ones that are done “correctly” by the state, often kill innocent people. And, as you said, people that have directly commited a crime still deserve their rights.
Situations like this, where no one wants to see a killer like that get away, it becomes easier to overlook bad policing, and everyone should make a conscious effort try and hold police to a higher standard to do things properly.