The shoot-to-kill policy grants police officers with authority to enact what is effectively a death sentence without judicial proceedings. That amounts to extrajudicial execution - whether or not you accept that.
Extrajudicial - Outside of the usual judicial proceedings.
Execution - The act or an instance of putting to death.
Whether or not a person is suspicious enough to warrant use of the powers granted by a shoot-to-kill policy is at the discretion of the police officer. That contravenes and erodes the concept of "innocent until proven guilty" which is a fundamental foundation in the judicial system. The shoot-to-kill policy contravenes several legal rights.
I don't know why you keep referring to whether or not a subsequent inquiry is made into whether the police officer was justified. This has nothing to do with corrupt systems. That is completely irrelevant to whether a shoot-to-kill policy contravenes the fact that someone is to be considered innocent until proven guilty.