Well, if it can be proven, that keeping that person alive puts other people in danger, I gues I would justify killing him.

But other than that, my view remains the same. A life sentence should be the max sentence. I don't belive in death as a form of punishment. It is immoral.

Who are we to judge who deserves death? Some that live deserve death, some that died deserve life. We can not give life to the dead, that deserve it, so we should not deal out death on judgement, but only out of necesity. If the person is in custody, he is no longer a danger to anyone. Our concerns should not reach beyond that.