“Y’know, “murder” isn’t in the Constitution, either. But there is a law against it... “
Correct, murder isn’t in the Constitution, and as such, it is used to be left to the states or people to determine how to handle this. And is therefore, illegal for the President and his branch at the federal level or any other entity within the federal government.
Murder committed on federal property (or in D.C.) has always been a federal crime and punishable by the feds.