Military prosecutors have re-filed capital charges against Khalid Sheik Mohammed and four co-defendants accused of orchestrating the attacks of Sept. 11, 2001, restarting a process that the Obama administration had halted as part of its failed effort to close the military detention center at Guantanamo Bay, Cuba.

Charges against the five men were withdrawn without prejudice and dismissed in January 2010 in anticipation of a federal trial in New York City. Bipartisan opposition scuttled that plan, and Attorney General Eric H. Holder Jr. announced in April that the defendants would be returned to a military tribunal at Guantanamo Bay.

Although the five defendants were first charged in 2008, and numerous pretrial hearings were held before the case was stopped, it must begin again with a fresh arraignment. Under military law, the defendants must first be referred for trial by a Pentagon official known as the convening authority, but that step seems certain in this case.

Among the first issues likely to be considered again is the defendants’ wish to represent themselves, which could have a major impact on how quickly the case moves to trial and a verdict. They are each entitled to a military attorney and “learned counsel,” a lawyer with experience in death penalty cases.

In the previous case, Mohammed and two other defendants — Ali Abdul Aziz Ali, a Pakistani who is Mohammed’s nephew, and Walid bin Attash, a Yemeni — won the right to represent themselves. A military judge was still deciding whether Ramzi Binalshibh, a Yemeni, and Mustafa al-Hawsawi, a Saudi, were competent to make that choice when the government withdrew the charges.

In the previous case, the defendants had said they were interested in pleading guilty to capital charges so they could be executed. It was unclear at the time whether that was permissible under military commission rules, and there has since been discussion in Congress about clarifying or amending the military commissions legislation to allow it.

The five men face multiple charges, including murder in violation of the law of war, attacking civilians, attacking civilian objects, hijacking aircraft and terrorism.