The US military judge overseeing court proceedings for the alleged plotters of the September 11, 2001 attacks is retiring, the Pentagon said, possibly triggering yet more delays to the slow-moving case. The so-called "9/11 Five" -- including alleged mastermind Khalid Sheikh Mohammed - have been locked up at the Guantanamo Bay military prison for years and were first charged in 2008.

But an unending slew of legal missteps, issues with military court proceedings and problems stemming from evidence extracted under duress have seen the men's prosecution morph into a quixotic attempt at justice.