Murder is defined as the unlawful killing of a human being by another human being with malice aforethought. In other words, only humans can be murdered and only humans can murder (because only we have the moral agency to allow us to be held accountable for unlawful homicides).
Two congressmen pushing for a new law banning videos that depict animal abuse—which depending on the details, would be fine with me—misuse the word in support of their bill. From their column:
Last week, the House of Representatives voted to outlaw the sale and distribution of graphic videos depicting the murder or abuse of animals by an overwhelming margin, passing the Prevention of Interstate Commerce in Crush Videos Act, 416 to 3.
This may seem like a small thing, but it really isn’t. Using the word “murder” to describe the unlawful killing of animals is just another way to blur the crucial distinction between us and fauna. Animals can certainly be abused. They cannot be murdered.