On Jan. 22, 2009, Pres. Barack Obama issued an Executive Order requiring the Guantanamo detention facility to be closed as soon as practicable. This report provides an overview of major legal issues likely to arise as a result of actions to close the Guantanamo detention facility. It discusses legal issues related to the transfer or release of Guantanamo detainees, the continued detention of such persons in the U.S., and the possible removal of persons brought to the U.S. Discusses constitutional issues that may arise in the criminal prosecution of detainees. Also discusses: detainees¿ right to a speedy trial, the prohibition against prosecution under ex post facto laws, and limitations upon the admissibility of hearsay and secret evidence.