And who or what body is it that your quotes are referencing? Who or what is carrying out the act of “due process of law” or “equal protection of the laws?”
You just gave one example of an exception: “without due process of law.”
The States define and determine things such as self-defense.
How about the Texas law that allows a homeowner to shoot someone who is in the act of stealing or invading his property?
How about the part of the Texas code, passed eight years ago by “pro-life” “Republicans,” which recognizes the personhood of the child from its creation, but then grants permission for abortionists to kill them, in obvious violation of the explicit requirements of the U.S. Constitution?
Don’t you think that question is much more appropriate to this conversation than trying to muddy the waters with questions about what may or may not constitute justifiable homicide?