:In reply, traditionally historians used the term "assassination". Sir Ian Kershaw states: "One of Hitler's most important henchmen, Heydrich...had been fatally wounded in an assassination attempt...Hitler always favoured brutal reprisals..." "Hitler A Biography", Kershaw, p. 713. Peter Padfield states: "Heydrich had been too successful...the Czech government in exile...needed to build up...(its)...declining bargaining position...Heydrich's assassination was to be the means." "Himmler", Padfield, p. 378. 

 :Your term, as you have defined it, is a newer more PC term that really is not needed. The term assassination can be used for Heydrich was an important public political Nazi official in the former Czechoslovakia; land incorporated into the Reich at that dark time in history. He was also, as you know, an important high ranking SS officer but a case can be made that it was more in his political capacity he was acting and a threat. Wikipedia, itself, sets it out as follows: "An assassination is the targeted killing of a public figure, usually for political purposes. Assassinations may be prompted by religious, ideological, political, or military reasons. Additionally, assassins may be motivated by financial gain, revenge, or personal public recognition. Assassination may also refer to the government-sanctioned killing of opponents or to targeted attacks on high-profile enemy combatants." For Heydrich, one can really use either for it was a ..."targeted killing of a public figure,...for political purposes" and "...government-sanctioned killing of (a) opponent, A/N/A an assassination." So I believe your definition is rather narrow for the reasons above.