I’m not giving you my opinion. I’m giving you the literal meaning of the word “posterity.”
A meaning you’re totally ignoring, and which is backed up by the clear meaning of the Fifth and the Fourteenth Amendments, and which was preceded by the clear words (self-evident ones) of the Declaration.
The Constitutional prohibition against taking life applies to the Federal government and/or the States. It does not require that a person exercise "due process of law" before exercising his right to self-defense.