When is murder murder?

Roger directed me to a grisly story about a serial pet rabbit decapitator and exsanguinator in Germany ("Rabbit ripper shocks Germany" http://animaladvocates.com/cgi-bin/newsroom.pl/read/20071). There have been 30 "victims" to date, and the police are worried that "the killer" might switch to killing people, which I assume would be a real problem.

Here's my question: When is murder murder? I believe according to the law in the US, the victim must be a human being, as must be the perpetrator. But many secondary and tertiary definitions I quickly looked up made no mention of the victims being human or even "persons" (which wouldn't include nonhumans but would, oddly, include corporations).

Kill is to take one's life, no matter who's defining the word, and there's no mention of humans of nonhumans. Slaughter is sort of the flipside of murder in that the primary definitions of the various dictionaries make particular mention of animals ("especially for food," they'll say). Secondary definitions include people, killed in either large numbers or in an especially brutal manner.

When I think of the taking of the life of a lamb or a fish or a cow, when not in self-defense, I cannot help but think of murder.

Strangely, a ripper (from the title of the article this post refers to and reminiscent of "Jack the-") is a murderer who specifically uses a knife to slash his victims (according to several dictionaries, although a ripper is a killer according to at least one other).

So the killer of the rabbits is indeed a ripper: a murderer.

I personally experience kill as a sterile word for some reason, and have no visceral reaction to it, perhaps because it doesn't imply malice or intent. Murder, on the other hand, with its intent to end a life, is a word I think we should be using more often when it comes to what we do--merely because we want to--to sentient nonhumans.

Now, there's always the mild, but perceptible jolt I often notice in the person I'm speaking with when I use , murder, when talking about animals. It's the same jolt you see when you say , flesh, . But, when used carefully and perhaps with an explanation of why it's an accurate word, , murder , could be an important part of the shifting of a paradigm whose shift is long overdue.

What do you think?