From a Department of Justice press release:
On July 30, 2009, consistent with the U.S. government's notice that it would no longer treat Jawad as detainable under the Authorization for Use of Military Force, a federal court ordered the U.S. government to release him from detention at Guantanamo Bay. On Aug. 6, 2009, in accordance with Congressionally-mandated reporting requirements, the administration informed Congress of its intent to transfer Jawad. Jawad's transfer was carried out under an arrangement between the United States and the government of Afghanistan. The United States has coordinated closely with the government of Afghanistan to ensure the transfer takes place under appropriate security measures and will continue to consult with the Afghan government regarding Jawad.
See Thomas Joscelyn on the Jawad case here.