When There's No AUMF Nexus: Abu Khattalla and Criminal Procedure

I seem to have arrived late to the Abu Khattalla party. But I concur most emphatically that he should be tried in a stateside civilian court. Under the circumstances, Guantanamo is simply a non-starter. Apropos, seeing how the United States apparently has treated Abu Khattalla's as a straightforward criminal matter, then what should we make of his extended detention aboard the U.S.S. New York? Quite unlike its earlier, hold-for-interrogation-then-prosecute cases (Ghailani, Warsame, and Al-Liby), the United States now claims---has---no power to hold Abu Khattallah under the 2001 AUMF and laws of war. And without a wartime nexus, the government's authority to detain for intelligence purposes prior to commencing criminal proceedings---rather than commencing criminal proceedings immediately---is less clear. In that regard, Abu Khattalla's case stands to create a more broadly applicable (and thus perhaps more consequential) precedent. It will be interesting to see how much, if at all, the detention affects litigation of the usual criminal procedure issues---among others, Miranda, and the general post-arrest obligation to present the defendant to a judge "without unnecessary delay."  As readers know, the latter is usually referred to as “presentment.” And it generally disallows delaying an accused's initial hearing in order to interrogate him about criminal offenses. The shipborne detention implicates Abu Khattalla's speedy trial rights too. (On this score, the Washington Post reports that the government has questioned the defendant pursuant to the Quarles “public safety exception” to Miranda—though I wonder whether that properly covers all interrogation, on any subject, undertaken since Abu Khattalla’s capture last weekend. I suppose the government might also intend to argue that presentment doctrines do not govern questioning for purely intelligence-gathering purposes. But this is mostly educated guess work; the facts aren’t sufficiently clear just yet.) This much is clear, however: the election of civilian process, coupled with a multi-day, post-capture detention, implies the prosecution's healthy confidence in the courts not rejecting, or even substantially narrowing, the criminal case against Abu Khattalla---AUMF hook or no.  The remedy for Miranda and presentment violations would almost certainly be suppression of statements made by Abu Khattalla during interrogation aboard the New York; we thus can infer that the United States amassed a trove of highly inculpatory, admissible evidence of the defendant's guilt, prior to capture, and that it consequently isn't depending on post-capture interrogation to furnish evidence for the criminal case.  (Citing former government officials, the Post certainly suggests as much in its coverage.) As for the accused's speedy trial rights, the Second Circuit recently found that even Ghailani's multi-year detention, by the CIA and then by the military at GTMO, didn't amount to a Sixth Amendment violation warranting dismissal---though, again, Ghailani was held initially pursuant to the AUMF. UPDATE: from the Times, we learn that

The Libyan suspected of playing a key role in the deadly attack on the United States Mission in Benghazi is talking freely with American interrogators aboard a Navy ship in the Mediterranean Sea, according to senior American officials.

There's also this, regarding presentment:

Obama administration officials have also raised an argument they could make to a judge if they wanted to present in court a statement made by Mr. Abu Khattala: The delay was not “unnecessary” because it was easier to bring him through international waters than to transport him by helicopter to an airport in a country in Europe or North Africa, which would require the permission of the host country.