The U.S. Justice Department is set to charge a Libyan man with constructing a bomb that detonated on a passenger plane over Lockerbie, Scotland, in 1988, killing 270 people and launching a decades-long international manhunt for the culprits.
According to a source familiar with the case who requested anonymity to speak about it before the charges are unveiled, the department is set to charge Abu Agila Mas'ud on Monday, exactly 32 years after that deadly flight. U.S. Attorney General William Barr holds a news conference on the case Monday morning.
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The charges will represent a closing of the circle for Barr, who tasked his then-criminal division chief, Robert Mueller III, to investigate the bombing during their earlier stint in government under President George H.W. Bush.
The attack cost the lives of 189 Americans, and it appears to have made a deep impression on both Barr and Mueller, who have appeared at annual remembrance ceremonies over the years, alongside the families of victims.
Mas'ud remains at large overseas. It's not clear when, if ever, authorities might be able to bring him to justice on American soil.
The only man convicted for his role in the bombing, Abdel Basset Ali al-Megrahi, died in 2012 after serving several years in prison. Scotland granted him compassionate release after his lawyers said he had cancer and was on the verge of death. He lived for about three more years.
Huge challenge to investigators
The Lockerbie investigation had been one of the most complex probes ever for the FBI, which helped conduct more than 10,000 interviews. Forensic experts eventually traced a thumbnail-sized bit of evidence to a cassette player they believe contained the bomb. The Libyan government took responsibility for the crime.
Former FBI Director Mueller, who went on to investigate Russia's attack on the 2016 election, talked with bureau officials years later about how the case touched him.
"The constables in charge of the Scottish end of the investigation had constructed a small wooden warehouse in which were stored the various effects of those who were on the plane when it broke apart in the skies: a white sneaker never again to be worn by the teenager, a Syracuse sweatshirt never again to be worn by the Syracuse student and other such everyday pieces of clothing and personal belongings," Mueller said.
Continued the director: "These ordinary items brought home to me — and came to symbolize for me — the pain and the loss felt by those whose family, friends or colleagues died that evening."
The attack killed all 259 people aboard the plane and 11 people on the ground.
The FBI's experience in the Lockerbie case pushed the bureau to launch a program to help crime victims and their relatives. Kathryn Turman, who went on to lead the victim services team, helped arrange a video feed of the proceedings in the al-Megrahi trial so that family members could watch.
Federal authorities in Washington trained new firepower on the case last year after conducting a review of counterterrorism matters that had languished.