In November 2008, Ali Hamza Suliman Ahmad Al Bahlul, who served as Osama bin Laden’s videographer and public relations secretary, was convicted by a military commission on charges of conspiracy, material support for terrorism, and solicitation.  On January 25, 2013, a three-judge panel of the United States Court of Appeals for the District of Columbia Circuit overturned Bahlul’s conviction, but the court subsequently granted the government’s petition asking that the full court rehear the case en banc.  In granting rehearing, the D.C. Circuit asked the parties to brief two questions not previously addressed, including whether the Ex Post Facto Clause applied to Guantanamo detainees.

On June 10, 2013, Constitutional Accountability Center filed an amicus curiae brief in the D.C. Circuit.  As our brief demonstrated, the Constitution’s text and history, as well as the Supreme Court’s decision in Boumediene v. Bush holding that the Suspension Clause applies to individuals detained at Guantanamo, all supported the application of the Ex Post Facto Clause in this case.  The Constitution’s prohibition on ex post facto laws was of paramount importance to the Framers, who viewed the prohibition to be both a structural safeguard and a protector of individual liberties.  Thus, they wrote the Constitution to prohibit the mere passage of an ex post facto law, and applied that prohibition to both the federal and state governments, making such laws completely forbidden in the new Nation.  This prohibition was designed to uphold the separation of powers as well as to ensure that individuals are given fair notice that certain conduct is criminally punishable.  The centrality of the Ex Post Facto Clause in the constitutional structure underscores that ex post facto laws become no more permissible because they are applied to individuals outside the formal borders of the United States, rather than inside.

The full D.C. Circuit heard oral argument in Bahlul on September 30, 2013, and issued its decision on July 14, 2014.  The court vacated Bahlul’s material support and solicitation convictions but rejected his ex post facto challenge to his conspiracy conviction, although it did assume that the Ex Post Facto Clause does apply to Guantanamo detainees.  Moreover, although the court did not actually decide whether the Ex Post Facto Clause applies to detainees at Guantanamo, five of the seven judges (Garland, Tatel, Griffith, Rogers, and Kavanaugh) indicated their belief that it does, as CAC had urged in our brief, while Judges Henderson and Brown disagreed.  Echoing our brief, Judge Rogers expounded on the importance of the Ex Post Facto Clause, describing it as “one of the few safeguards of liberty specified in the Constitution” that “serves both to protect individuals and to preserve the Constitution’s separation-of-powers structure.”