A nation of laws does not permit the police to be also the judges and the executioners. It is one short step to death squads.
Besides, they had no idea who [else] was in the cabin.
Killing Dorner this way is guaranteed to make him a martyr among those who approved his methods. A trial would have exposed his crimes and showed him for what he was (an angry egotist who was only concerned about what OTHERS do to HIM.) Hardly a word in his manifesto is dedicated to what he did to others. The manifesto, actually, opens with declaration that his actions, however evil, are necessary and should be properly understood by the unwashed masses. You can't get more narcissist than that.
A dead idol is very convenient. He holds no surprises - he already has done all his activities. He already said all that he is ever going to say; but new words can be easily attributed to him, and who is going to challenge that? This is why martyrs are idolized. It's much easier to wear a T-shirt with Che Guevara's photo than to deal with the live Che who would shoot you on sight if he wants to.
I like threads like this. It clearly highlights that a number of supposed conservatives, who purportedly support the Free American Republic, as laid out by the Founding Fathers and codified in all their voluminous writings, actually support a Standing Police Army that snuffs out its enemies with incendiary devices and overwhelming brute force.
The point they neglect is that this Standing Police Army is in the control of tyrants like Dianne Feinstein and Barack Obama, who WILL use the SPA against them when the time comes.
This is a concern because there was a direct line between Waco and the OKC bombing. Not a moral justification for OKC, but these sort of things happen when government doesn’t consider anything other than the short term effects of its actions.