An elk cow and her calf are grazing on the grass in a national park area. A tourist, ignoring the many signs posted in the area steps over the low fence and approaches the elk and her calf to get a better picture. The elk watches his approach warily and then suddenly attacks. With the powerful kicking of her legs the tourist is in real danger of being killed.

A wildlife protection officer happens to be near by and holding a rifle. Should the officer use his rifle to kill the elk protecting her calf to save the life of the marauding tourist?

Yes or no?

Defend or explain your answer on a moral basis. Forget legal or economic issues like liability. Explain why saving one life is more important than the other.