Police have a mandate to protect life and property. It's in their job description.
No, actually, they don't have any such mandate under US law; according to the US Supreme Court. The only mandate police have is to enforce laws and apprehend those suspected of crimes. Protecting life and property is not in their job description.
Civilian property owners do not have this mandate. They have a mandate to protect their own lives. Police should therefore have a little more leeway around their decision to use lethal force.
Again, this is where US and Oz law and culture differ. In the US, protection of life and property is primarily the onus of the individual, not law enforcement.
The only privileges that LEOs maintain that civilians do not are the ability to carry firearms in places that are normally restricted for civilians, and a much wider latitude in use of force to apprehend, detain, and search individuals suspected of criminal activities.
In the US civilians have a limited ability to detain individual suspects, known as "citizen's arrest", but this is a very problematic gray area even under best-case circumstances. In the US, citizens are also permitted to use the same degree of lethal force to defend others that they would be allowed in self-defense.
"Castle Doctrine" is predicated on the principle that any unauthorized intruder found within a dwelling not their own can be presumed to present a "clear and present danger" to anyone residing therein, and therefore the owner/resident is justified in responding with lethal force, and has no onus to ascertain the degree of threat posed by the intruder, or to retreat from any perceived threat within a domicile they lawfully inhabit.
Certain implementations of the "Castle Doctrine" provide even more leeway in the use of lethal force, but that varies greatly be jurisdiction, and some go much to far in what they allow, IMO. The definition of "clear and present danger" also varies considerably. Some also expand "Castle Doctrine" to include protection of property, or certain additional types of property outside of a domicile, such as automobiles.
I, for one, am perfectly fine with reining in police use of lethal force to roughly the same degree as is permitted for civilians under similar circumstances.
Furthermore, police are trained. They are trained in law and law enforcement - in theory, at least. Civilians are not. A gun in the hands of a cop is not the same as a gun in the hands of a citizen.
Given the actions of police in the US, it's clear that their training does not make them significantly better at protecting life and property than the average untrained citizen. Particularly when that training actually emphasizes and encourages escalation of force. And as the number of bystander casualties has demonstrated, even when they are justified in using lethal force, their degree of skill in doing so does not always rise significantly above that of untrained civilians.
