I suppose in the extreme case political asylum seekers who come to America and get safe asylum are similar to this criminal being harbored by Canada. Would America extradite political dissidents back to their homelands if they were sure to be executed?

I suppose it all boils down to what value you put on human life. In America the value of your life is conditional upon how much you contribute to society or rather how much take away from it. If you are innocent like a new born or fetus you are valued because you haven't done any bad in our life. But if you kill or rape someone then you deserve to die. The value of your life to society is conditional your life means nothing to others if you are a criminal. Three strikes...throw away the key and rot in hell.

In some counties the value of human life is unconditional and their justice system revolves around rehabilitation not vindictive punishment so they would naturally see killing as a means of punishment odd.