The killing by drones in Yemen of American citizens Anwar al-Awlaki, in September 2011, and his son, Abdulrahman, a few weeks later has continued to be a major issue among lawyers and constitutional scholars, and a subject of discussion and debate since the deaths were announced. The legality of the killings became national news recently when Sen. Rand Paul mounted a 13-hour filibuster to delay the confirmation of John Brennan, President Obama’s former national security adviser, as the new director of the Central Intelligence Agency. Fuel was also added to this legal fire by the leak of a “summary white paper” of the legal opinion that justified the use of drones to kill American citizens who had not been tried or convicted of any crimes by an American court.

Let me be clear, from all of the information available, Al-Awlaki was a high level member of  Al-Qaeda in Yemen although his son’s killing was apparently a terrible mistake and no public information connects Abdulrahman to Al-Qaeda or any terrorist organization. Sen. Paul asked Attorney General Eric Holder whether the administration intended to use drones to kill Americans on U.S. soil. After some delay, the attorney general answered that there was no such intent, but whether the administration believes that it has the legal right to do so remains up in the air. It also seems fairly clear that the administration does believe that it has the right to use drones to attack and kill Americans, under certain circumstances abroad, as it did in the case of Anwar Al-Awlaki.

Many lawyers — and I’m among them — find the administration’s position on the use of drones to kill American citizens without affording them any due process of law quite troubling because it would appear to set a very dangerous precedent never before even considered to be acceptable by the federal government. What is even more troubling is that the administration has steadfastly refused to make public all of the documents and reasoning it used to determine that these drone attacks against American citizens without any trial or conviction. Thus, it is impossible for anyone outside the current administration either to determine the precise extent of the powers that President Obama is now claiming or to make reasoned criticisms of these powers and their legal justification.

This lack of transparency and the existence of secret memoranda and opinions is troubling in itself and also because, when President Obama ran for his first term, he and his supporters were highly critical of President Bush’s use of “enhanced interrogation techniques” — what many have called torture — and the memoranda prepared by administration lawyers to provide legal justifications for these techniques.

There seems to be a bit of hypocrisy at play here. For my own part, it seems to me that the killing of American citizens without trial is no less troubling than the use of enhanced interrogation techniques like water boarding against terrorists. At least the terrorists survived to challenge what had been done to them.

I remember an experience I had several years after the Oklahoma City bombing. Then Gov. Bill Graves asked me to go to western Kansas and meet with some militia members to try to understand their grievances. So I drove out and met with several militia members in an old courthouse.

One of the first things they told me was that they feared that the day would come when black armored helicopters would fill the skies over their farms and murder them and their families. I immediately told them that was crazy, that no American government would ever kill its citizens without due process of law.

Now, I’m beginning to wonder. Except if it happens, whoever is the target won’t even have the warning of hearing a helicopter’s rotors. Instead there will just be silence, ruptured by the explosion of a Hellfire missile. I hope this never happens. But I think it is time for the Obama administration to release all of the relevant materials they used to justify the legality of drone strikes against American citizens and permit this policy to be debated openly by Congress and the American people.

Mike Hoeflich, a distinguished professor in the Kansas University School of Law, writes a regular column for the Journal-World.