If someone is actively attacking the police with lethal force, they already have the right to shoot that person in self defense or the defense of others. However, if you're referring to a situation where someone is not an imminent threat to anyone's safety or if they were a threat they have been subdued, then NO the police, military, border patrol etc. don't have a right to shoot that person. Remember, at least one January 6th prisoner is still in jail because they reportedly bumped into a police officer and that was considered "assaulting" a police officer. That was clearly a miscarriage of justice and a very slippery slope we should not go down.