Murder makes the intent sound more petty; less important, more personal, and less political than it really is
Assassination indicates political intent and societal effect, and even a sketchy history of skeletons behind the assassinated that led to this
But the cultural hegemonic capitalist lib and con media don't wanna hear anything about such history.
As a Brazilian, this makes me wonder what would be the equivalent terms in Portuguese, because "murder" translates to "assassinato" and "assassination" also translates to "assassinato".
"Homicídio", at least in Portugal
Isn't "homicídio" more like a broad term which includes unintentional deaths (which we'd call as "homicídio culposo")?
Both of the terms "murder" and "assassination" imply intention, with the intention behind an "assassination" being a political/ideological one rather than the intention behind a "murder" (which would be more personally-oriented intentional homicide).
My question is because I can't remember of a Portuguese term that carries a political/ideological sense when referring someone killing another. Portuguese-speaking media outlets here in Brazil often use "morte" e "assassinato" interchangeably, even though "morte" is an even-broader term referring to "death".
Perhaps the Brazilian media lacks an equivalent word, too. "Globo" (one of the major media outlets here), for example, is using the term "assassinato":
*removed externally hosted image*
Even UOL, another major media outlet which is said to be more left-leaning, is also using the term "assassinato":
*removed externally hosted image*
So, as the OP said, these headlines, especially in Portuguese, "makes it sound unwarranted".