In addition to pursuing the death penalty where possible, the Attorney General shall, where consistent with applicable law, pursue Federal jurisdiction and seek the death penalty regardless of other factors for every federal capital crime involving:
(i) The murder of a law-enforcement officer; or
(ii) A capital crime committed by an alien illegally present in this country.
The Attorney General shall encourage State attorneys general and district attorneys to bring State capital charges for all capital crimes with special attention to the crimes described in Subsections (i) and (ii), regardless of whether the federal trial results in a capital sentence.
Many states in the US explicitly say you can resist an officer using force when they shouldn’t. Many juries, DAs, and other cops in said states won’t give a shit.
As for the going against the constitution, the word murder in the executive order basically removes any contradiction, because murder is a legal term in the various penal codes and wouldn’t fit someone who had shot a cop lawfully.