To my ears (and eyes), the verb kill has a negative connotation which describes a causal relationship to the death of a person, animal or animate matter in a unfair and judgmental manner when there is no direct agency to ascribe the responsibility. Because I shun, excuse me, eschew such usage, I like to substitute the verb die in its various tenses; i.e., "he died from a fall from a four-story window" instead of "the drop from the four-story window killed him."
This is unless I am talking about a scenario involving a conscious attempt of life-taking, in which case I would prefer kill for justifiable or accidental homicide, and murder when it's neither. So if I shoot an aggressing brigand in self-defense it's the former, while if I did the same to a pencil thief, my improportionate response would be tantamount to murder according to a libertarian theory of justice.
It's not a watertight distinction. If someone commits suicide, I don't know if that counts as killing one's self or self-inflicted murder. Or deaths stemming from a reckless driver's car accident, an event he didn't want to eventuate but none the less contributed to by operating his vehicle in a manner not conducive to a safe-driving habitat.
I find that many folks are in this habit of using the word kill to push forward their political agenda (and I'm not specifically referring to anti-abortionists.) For example anti-development zealots will decry the unfortunate plight of construction workers "being killed on the job" to shamelessly push forth their agenda of a housing or commercial stasis.