(if he were not above it, of course)
18 USC § 1111 (a): "Murder is the unlawful killing of a human being with malice aforethought. Every murder perpetrated by poison, lying in wait, or any other kind of willful, deliberate, malicious, and premeditated killing; or committed in the perpetration of, or attempt to perpetrate, any arson, escape, murder, kidnapping, treason, espionage, sabotage, aggravated sexual abuse or sexual abuse, child abuse, burglary, or robbery; or perpetrated as part of a pattern or practice of assault or torture against a child or children; or perpetrated from a premeditated design unlawfully and maliciously to effect the death of any human being other than him who is killed, is murder in the first degree."
I get what you're saying, that he wasn't the triggerman, but we get him here:
18 USC § 1117: "If two or more persons conspire to violate section 1111, 1114, 1116, or 1119 of this title, and one or more of such persons do any overt act to effect the object of the conspiracy, each shall be punished by imprisonment for any term of years or for life."
So he is guilty (allegedly) of "Conspiracy to Murder", and so is the entire chain of command and the entire Terror Teusday metting group. We don't call that brand of convict murder conspirators, any more than we call anyone a possession with intent to distribut[or]. We call the latter drug dealers and the former murderers. I don't think either is a misnomer.
Please don't take my example to be support for the War on Drugs.