From a joint press release:

The American Civil Liberties Union and the Center for Constitutional Rights (CCR) today filed a lawsuit challenging the government’s asserted authority to carry out “targeted killings” of U.S. citizens located far from any armed conflict zone.

The authority contemplated by the Obama administration is far broader than what the Constitution and international law allow, the groups charge. Outside of armed conflict, both the Constitution and international law prohibit targeted killing except as a last resort to protect against concrete, specific and imminent threats of death or serious physical injury. An extrajudicial killing policy under which names are added to CIA and military “kill lists” through a secret executive process and stay there for months at a time is plainly not limited to imminent threats.

“The United States cannot simply execute people, including its own citizens, anywhere in the world based on its own say-so,” said Vince Warren, Executive Director of CCR. “The law prohibits the government from killing without trial or conviction other than in the face of an imminent threat that leaves no time for deliberation or due process. That the government adds people to kill lists after a bureaucratic process and leaves them on the lists for months at a time flies in the face of the Constitution and international law.”

The groups charge that targeting individuals for execution who are suspected of terrorism but have not been convicted or even charged – without oversight, judicial process or disclosed standards for placement on kill lists – also poses the risk that the government will erroneously target the wrong people. In recent years, the U.S. government has detained many men as terrorists, only for courts or the government itself to discover later that the evidence was wrong or unreliable.

According to today’s legal complaint, the government has not disclosed the standards it uses for authorizing the premeditated and deliberate killing of U.S. citizens located far from any battlefield. The groups argue that the American people are entitled to know the standards being used for these life and death decisions.

“A program that authorizes killing U.S. citizens, without judicial oversight, due process or disclosed standards is unconstitutional, unlawful and un-American,” said Anthony D. Romero, Executive Director of the ACLU. “We don’t sentence people to prison on the basis of secret criteria, and we certainly shouldn’t sentence them to death that way. It is not enough for the executive branch to say ‘trust us’ – we have seen that backfire in the past and we should learn from those mistakes.”

CCR and the ACLU were retained by Nasser Al-Aulaqi to bring a lawsuit in connection with the government’s decision to authorize the targeted killing of his son, U.S. citizen Anwar Al-Aulaqi, whom the CIA and Defense Department have targeted for death. The complaint asks a court to rule that using lethal force far from any battlefield and without judicial process is illegal in all but the narrowest circumstances and to prohibit the government from carrying out targeted killings except in compliance with these standards. It also asks the court to order the government to disclose the standards it uses to place U.S. citizens on government kill lists. [my emphasis]

For the backup documentation, go here or here.