Palmer has been called a murderer who should be hanged. While the thrill killing of an animal is fraught with moral peril (it is morally wrong to kill anything just to kill it) it is nonsense to argue that Cecil was murdered. Animals cannot be murdered: they are not on a high enough moral plain to merit that charge. His crime, if he did commit one, was in breaking the law. He may have violated Zimbabwean conservation law. He did not murder that lion.
It is interesting to note that Zimbabweans themselves are surprised at the reaction of the United States and many westerners. In a recent article from AOL, they seem surprised. With all the other (and more pressing) issues they face, the uproar over killing a lion they find somewhat absurd. You may read about it here: http://www.aol.com/article/2015/07/30/zimbabwean-baffled-by-foreign-concern-for-killed-lion/21216119/?icid=maing-grid7%7Cmain5%7Cdl2%7Csec3_lnk3%26pLid%3D903214704 And indeed, there are westerners to whom it is much ado about nothing, considering the horror of things such as the abortion of human babies which we permit.
We reject that it is much ado about nothing. Proper anger over a thrill kill is fine, and it's wrong to be dismissive of that fact. Yet there is a question which we'd love to know: is Ricky Gervais, a celebrity in the forefront of the fight against big game hunting (which is exactly the sort of thrill killing which is abhorrent) for abortion? How many people aghast at the killing of a lion are for it? These are legitimate questions because it would take from them the moral high ground.
We ask that because it would demonstrate the lack of a rational moral compass on the part of such folks. As such, their view on any moral issue should be held suspect. But having said that, the right degree of concern about the wanton killing of animals is a moral good which should be encouraged.
At the end of the day we should be against thrill kills even of animals. Yet we also need to understand that they are just animals who do not merit the same moral concern as human beings facing human ills. Animal neglect and abuse is, properly, against the laws of most nations. But it is not the worst sin one might commit.