The decision (PDF):

http://gulcfac.typepad.com/georgetown_university_law/files/al.marri.cta4.decision.pdf

UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT
No. 06-7427
ALI SALEH KAHLAH AL-MARRI, Petitioner - Appellant,
and MARK A. BERMAN, as next friend, Petitioner,
versus
COMMANDER S. L. WRIGHT, USN Commander,
Consolidated Naval Brig., Respondent - Appellee.

Appeal from the United States District Court for the District of
South Carolina, at Charleston. Henry F. Floyd, District Judge.
(2:04-cv-002257-HFF)

Argued: February 1, 2007
Decided: June 11, 2007

Before MOTZ and GREGORY, Circuit Judges, and Henry E. HUDSON,
United States District Judge for the Eastern District of Virginia,
sitting by designation.

Reversed and remanded by published opinion. Judge Motz wrote the
opinion, in which Judge Gregory joined. Judge Hudson wrote a
dissenting opinion.

. . . DIANA GRIBBON MOTZ, Circuit Judge:

    For over two centuries of growth and struggle, peace and war, the Constitution has secured our freedom through the guarantee that, in the United States, no one will be deprived of liberty without due process of law. Yet more than four years ago military authorities seized an alien lawfully residing here. He has been held by the military ever since -- without criminal charge or process. He has been so held despite the fact that he was initially taken from his home in Peoria, Illinois by civilian authorities, and indicted for purported domestic crimes. He has been so held although the Government has never alleged that he is a member of any nation’s military, has fought alongside any nation’s armed forces, or has borne arms against the United States anywhere in the world. And he has been so held, without acknowledgment of the protection afforded by the Constitution, solely because the Executive believes that his military detention is proper.

    While criminal proceedings were underway against Ali Saleh Kahlah al-Marri, the President ordered the military to seize and detain him indefinitely as an enemy combatant. Since that order, issued in June of 2003, al-Marri has been imprisoned without charge in a military jail in South Carolina. Al-Marri petitions for a writ of habeas corpus to secure his release from military imprisonment. The Government defends this detention, asserting that al-Marri associated with al Qaeda and “prepar[ed] for acts of international terrorism.” It maintains that the President has both statutory and inherent constitutional authority to subject al-Marri to indefinite military detention and, in any event, that a new statute -- enacted years after al-Marri’s seizure -- strips federal courts of jurisdiction even to consider this habeas petition.

    We hold that the new statute does not apply to al-Marri, and so we retain jurisdiction to consider his petition. Furthermore, we conclude that we must grant al-Marri habeas relief. Even assuming the truth of the Government’s allegations, the President lacks power to order the military to seize and indefinitely detain al-Marri. If the Government accurately describes al-Marri’s conduct, he has committed grave crimes. But we have found no authority for holding that the evidence offered by the Government affords a basis for treating al-Marri as an enemy combatant, or as anything other than a civilian.

    This does not mean that al-Marri must be set free. Like others accused of terrorist activity in this country, from the Oklahoma City bombers to the surviving conspirator of the September 11th attacks, al-Marri can be returned to civilian prosecutors, tried on criminal charges, and, if convicted, punished severely. But the Government cannot subject al-Marri to indefinite military detention. For in the United States, the military cannot seize and imprison civilians -- let alone imprison them indefinitely.

[ . . . ]

Footnote 16, pages 58-59:

    The Government’s treatment of al-Marri, i.e. subjecting him to military detention, which the Government insists “is not ‘punishment,’” is at odds with the Government’s repeated recognition that criminal terrorist conduct by aliens in this country merits punishment by a civilian court, not indefinite military detention as an enemy combatant. [ . . . ]

    The Government’s treatment of others renders its decision to halt al-Marri’s criminal prosecution -- on the eve of a pre-trial hearing on a suppression motion -- puzzling at best. Al-Marri contends that the Government has subjected him to indefinite military detention, rather than see his criminal prosecution to the end, in order to interrogate him without the strictures of criminal process. We trust that this is not so, for such a stratagem would contravene Hamdi’s injunction that “indefinite detention for the purpose of interrogation is not authorized.” 542 U.S. at 521. We note, however, that not only has the Government offered no other explanation for abandoning al-Marri’s prosecution, it has even propounded an affidavit in support of al-Marri’s continued military detention stating that he “possesses information of high intelligence value.” See Rapp Declaration. Moreover, former Attorney General John Ashcroft has explained that the Government decided to declare al-Marri an “enemy combatant” only after he became a “hard case” by “reject[ing] numerous offers to improve his lot by . . . providing information.” John Ashcroft, Never Again: Securing America and Restoring Justice 168-69 (2006).

If your snark detector is functional, it should have gone into the red at the words, "We trust that this is not so."

As Marty Lederman noted at Balkinization, one can't credibly argue, "we gotta detain him somehow" - - for somebody who has already been detained.

http://salon.com/wire/ap/archive.html?wire=D8PNC7A80.html

June 12,2007 | WASHINGTON -- Special Prosecutor Patrick Fitzgerald urged a federal judge Tuesday not to delay former White House aide I. Lewis "Scooter" Libby's 2 1/2-year prison sentence.
[ . . . ] U.S. District Judge Reggie B. Walton [ . . . ] did not set a date for Libby to report to prison, however, and scheduled a hearing on the issue for Thursday. [ . . . ] If Libby's request to remain free is denied, defense attorneys will rush to an appeals court and ask judges there to put the sentence on hold. - - © 2007 The Associated Press.