WASHINGTON — Ahmed Abu Khattala insisted he was only a bystander as the gunfire crackled and then exploded after sundown five years ago in Benghazi, Libya.
Starting Monday, he is set to stand trial in Washington for conspiring to kill four Americans as the accused ringleader of the lethal, nighttime assaults on US diplomatic and intelligence facilities in September, 2012.
Abu Khattala, a 46-year-old Libyan who was a leader in an extremist anti-Western militia, is the only person to face trial in the United States for the fatal attacks that included US ambassador J. Christopher Stevens among its victims.
In announcing Abu Khattala’s capture in June 2014, during a secret nighttime raid by US commandos, then-president Barack Obama said efforts to bring those responsible for the attacks were continuing but ‘‘with this operation, the United States has once again demonstrated that we will do whatever it takes to see that justice is done when people harm Americans.’’
Abu Khattala has pleaded not guilty to 18 counts including conspiracy, murder, and material support of terrorists for the deaths of Stevens, State Department communications expert Sean Patrick Smith and security contractors Tyrone S. Woods and Glen Doherty.
He faces up to life in prison if convicted in federal court.
In repeated interviews with Western journalists in Benghazi where he lived openly before his capture, Abu Khattala, a former auto mechanic and political prisoner of Libyan dictator Moammar Gadhafi, denied his involvement in the attacks, but gave contradictory explanations of his role.
A jury of 12, plus three alternates, was selected in September to hear the first major terrorism trial in the United States since 2015, and the first in the nation’s capital since before the Sept. 11, 2001 attacks.
The jurors include a preschool teacher, retired FBI information technology worker, English professor, stamp designer, and manager in a landscape design firm, among other fields. The trial is expected to last four to six weeks.
Prosecutors are expected to call dozens of witnesses including families and relatives of victims, US security personnel involved in rescue operations on the ground, and multiple Libyan nationals and eyewitnesses to testify against Abu Khattala using pseudonyms for their and their families’ safety.
In sealed proceedings before the trial start, both sides have winnowed tens of thousands of pages of classified information for use in open court, including phone records prosecutors allege Abu Khattala placed from the scene at the time of assault.
Testimony is expected to elicit the first public statements from witnesses whose views have been summarized by congressional investigators, a State Department review board, and in a 2016 feature film based on a book written with the participation of security teammates of Woods and Doherty.
The trial will return a focus to the criminal prosecution of a five-year old attack that created an enduring diplomatic and political minefield for Obama and his secretary of state, Hillary Clinton, that extended through the 2016 presidential election.
Obama approved Abu Khattala’s capture by US Special Operations forces, holding it out as a model of how to try terrorist suspects in civilian courts despite objections of Republicans in Congress, including then-Alabama senator and now-US Attorney General Jeff Sessions.
Before joining the Trump administration to head the Justice Department, Sessions had argued that terrorism suspects should be detained at Guantanamo Bay and prosecuted by military tribunals.
The Libyan government also had protested Abu Khattala’s capture as a violation of Libyan sovereignty, inflaming tensions in that country’s bloody civil war after the US-backed overthrow of Gadhafi.
And during her presidential run, Clinton confronted partisan critics who asserted her actions as secretary impeded rescue operations, which she emphatically denied and several investigations debunked.
One of those investigations into the attacks disclosed that Clinton had used a private
e-mail address and server as secretary.
Abu Khattala’s prosecution has already yielded a legal ruling giving US authorities flexibility in blending civilian and military options to interrogate militants seized overseas.