Where was the due process for Abdulrahman al-Awlaki, a 16 year old American who was killed by a drone strike without any evidence of being involved as a combata

Where was the due process for Abdulrahman al-Awlaki, a 16 year old American who was killed by a drone strike without any evidence of being involved as a combatant or part of an insurgent group? As far as I can tell, there was never any official comment by any government official about this despite countless inquiries. Never any accountability. Hence my argument, due process is less relevant than ever these days. It is not at all out of the question for Snowden to be considered an enemy combatant, especially since we apply that same logic to any adult male in the vicinity of a drone target.