1. The court considers whether police used excessive force in violation of the Fourth Amendment to the U.S. Constitution. If yes, the court moves to part two of the test. If no, qualified immunity is immediately granted.
2. The court determines whether police should have known their actions violated the Constitution because court precedent clearly established their conduct as unlawful. If yes, the case goes to trial. If no, qualified immunity is granted.
Cases need nearly identical circumstances and in the same court jurisdiction for precedent to be "clearly established". Most cases are dismissed outright so that new precedent is never established, which leads what's "clearly established" being frozen in time.
[1] https://www.reuters.com/investigates/special-report/usa-poli...