Which ones? He killed over 70 people. Im sure each family would have a different idea on what to do. Also, I'd hate to live in a society which allowed victims families instead of a judges to pass sentences on people. Many may see it as alright in this case but it likely wouldnt take long to fall into tribalism. Victim impact statements, sure. Sentencing? No.
We see that in other societies - blood money is one aspect - as to humane punishment- that is a very broad brush to use.