It seems to me that the ACLU and CCR may be reading too much into this report that the U.S. government intends to actually file a criminal indictment against extremist cleric Anwar al-Awlaki, who is purported to be on the U.S. "kill list." Here's the joint statement:
Our organizations have long stated that if the government has evidence that Anwar Al-Aulaqi is involved in terrorist activity, it should present that evidence to a court – not authorize his execution without charge or trial. Now, months after the government announced its intent to kill Al-Aulaqi, it may finally bring charges against him. This would be a step in the right direction. The constitutional guarantee of due process relies on the critical distinction between allegations and evidence. If the reports that charges may be brought against Al-Aulaqi are true, the fact that it has taken the government this long – months after having announced his death sentence – suggests that, in this case, the government's allegations were far ahead of its evidence.
While bringing charges against Al-Aulaqi based on credible evidence would be a step in the right direction, it would not mean that he could now be targeted for killing without trial. It is well established that the government cannot use extrajudicial killing to punish people for past acts, but only to prevent grave and imminent threats. A criminal charge for past crimes does not provide a license to kill.
There have been rumors of an al-Awlaki indictment for months -- there's nothing in the report to suggest that one is particularly imminent. Both the rumors and the indictment itself, given after the government has already all but publicly asserted the authority to kill him without trial, seem designed to simply bolster the administration's public case for doing so. The biggest problem with indicting al-Awlaki at this point, from the government's perspective, is highlighted by the AP: To do so they'd have to actually accuse him of a crime for which killing him would be a justifiable response.