Qualified immunity shields government officials from personal liability in federal lawsuits unless they violate “clearly established” federal law. That means that even if a police officer violates someone’s constitutional rights, the victim can’t obtain damages from the officer unless he or she can show that the officer violated a right explicitly recognized by a prior court ruling.
In theory, this requirement protects government defendants from unexpected liability when law changes. In practice, courts apply the doctrine aggressively to shield officers from lawsuits unless plaintiffs can point to other cases declaring essentially identical conduct unconstitutional — a difficult hurdle, even when police conduct appears clearly wrong.
Indeed, even if the former police officer Derek Chauvin is convicted of murdering Mr. Floyd, it’s quite plausible that a court could refuse to hold him liable for violating Mr. Floyd’s constitutional rights if his lawyers were unable to point to an earlier case making clear that the specific action Mr. Chauvin took — kneeling on a restrained person’s neck for more than eight minutes — was unconstitutional.”