I am not a fan of these questions, but they are so common. Obviously if you are given the change to save many against one, then it is okay. This is a tough ethical question because death results in either decision. I really don't understand why psychologists ask this question.
Of course i believe that one death to save many is an acceptable trade, i grew up on star trek. So long as the person making that choice is willing to be the one death, i have no issue at all. In all seriousness however, some times hard choices must be made, i only hope i never have to be the one making them.
If they have to spend the rest of their life behind bars, why not save the tax payers money. They won't be happy,but maybe they shouldn't have committed the crime in the first place. The criminal has his appeals on death row,but if found guilty through and through, they deserve the outcome.
Yes, it can be consider acceptable (though not ideal) to kill or let one person die if that actions saves the lives of several other people. Of course this seems reprehensible, however when considering simply a choice between "kill one," or "kill a few," in that case, the death of only one person is obviously less bad.
If a person is innocent and not an imminent threat it is never acceptable to end their life no matter how many people it would save. I believe this would lead to a very slippery slope of unjustified killings. One person's life is no more valuable then anther's and killing that person may have unforeseen negative effects as well.