Viewpoints on death penalty?

Even though it has not been proven to be a deterrent to crime, it is morally necessary. The most heinous crimes that can be committed are those who are serial murderers, rapists and child abusers/pedophiles. A lifetime in prison is a gift for the perpetrator/predator which is paid for, through tax dollars, by the grieving family and loved ones of the innocent victim. This is pure BS.