When President Obama decided sometime during his first term that he wanted to be able to use unmanned aerial drones in foreign lands to kill people -- including Americans -- he instructed Attorney General Eric Holder to find a way to make it legal -- despite the absolute prohibition on governmental extra-judicial killing in federal and state laws and in the Constitution itself.
"Judicial killing" connotes a lawful execution after an indictment, a jury trial, an appeal and all of the due process protections that the Constitution guarantees defendants. "Extra-judicial killing" is a targeted killing of a victim by someone in the executive branch without due process. The president wanted the latter, and he wanted it in secret.
He must have hoped his killing would never come to light, because the Fifth Amendment to the Constitution could not be more direct: "No person shall be ... deprived of life, liberty or property without due process of law."
Due process has a few prongs. The first is substantive, meaning the outcome must be fair. In a capital murder case, for example, the defendant must not only be found guilty by a jury, but he also must truly be guilty.
The second prong of due process is procedural. Thus, the defendant must be charged with a crime and tried before a neutral jury. He is entitled to a lawyer, to confront the witnesses against him and to remain silent. The trial must be presided over by a neutral judge, and in the case of a conviction, the defendant is entitled to an appeal before a panel of three neutral judges.
The third prong of due process means that the defendant is entitled to the procedures "of law," that is, in the federal system, as Congress has enacted.
There are numerous additional aspects of due process, the basics of which emanate from the Constitution itself. Yet, the "of law" modifier of the constitutional phrase "due process" gives Congress, not the president, the ability to add to the due process tools available to a defendant. Congress may subtract what it has added, but neither Congress nor the president may remove any of the tools available to the defendant under the Constitution.