If I decide I really want to kill you, what should be the minimal punishment?
Life in prison.
Murder is a legal term. Administering a death penalty is not murder, since it is not a crime.
Murder is not exclusively a legal term; it is also used in ethical/moral discussions, like how I used it. A government can decide legallity, but it cannot decide if something is moral or not, although most governments attempt to do so. What is moral or not is also not universal, and can vary across different cultures and time periods.
But don’t go slandering people that disagree with you.
You mean like what you just did with this comment?
Keep in mind, in the US, there is a ~4% false conviction rate for the death penalty. That means that ~4% of people who get the death penalty are innocent.