You're citing a memo written by the people who ordered the assassination. But we are a nation of laws, and there is no law that says the government can order your assassination without charging you with a crime, finding you guilty and sentencing you. Which at that point, makes it no longer an assassination but an execution. Without the judicial procedures to justify it, it's just an assassination with a memo written by the killers.
>“The process determining criteria for killing is not public…”
>Knowing about it is not very useful if you don’t know the criteria. It’s not very helpful at all, in fact, in determining legality here.
No, the fact that the government doesn't make the criteria public is exactly how we know it isn't legal. There is no judicial process tied to it that accords rights to the accused. Therefore it's unconstitutional by definition.