Re extrajudicial: That’s a very specific definition. Here are a few others with sources:
Oxford: Outside the ordinary course of law or justice; not legally authorized; unwarranted.
Merriam Webster: not forming a valid part of regular legal proceedings, delivered without legal authority, done in contravention of due process of law
Dictionary.com: beyond, outside, or against the usual procedure of justice; legally unwarranted:
Security officers are given the power to make these decisions from their governments and the courts. Any court in the world would uphold the officer’s decisions to shoot, and it would therefore be considered to have legal authorization/within the usual procedure of justice.
Re cold-blooded: To me a “cold-blooded” murder is when a person kills another with no reason to kill that specific person. In the case of al-Hashlamun, I suppose there was some reason to target this person as an attack against settlers, but those specific people were not involved in al-Hashlamun’s murder. I’m not sure; I think it’s a different kind of case.
In the case of Israeli officers shooting at an attacker, there is a clear and legitimate reason for them to target that specific person. It’s not arbitrary or random. In that sense I don’t think it should be considered “cold-blooded”.