The scene of devastation caused by the explosion of a 747 Pan Am jumbo jet over Lockerbie, Dec. 22, 1988.

Local resident Robert Love stands by one of the four engines of the ill-fated Pan Am 747 jumbo jet, Dec. 22, 1988, that exploded and crashed the day before on the route to New-York, with 259 passengers on board.

A view taken December 22, 1988, of pieces of the wreckage of the 747 Pan Am airliner that exploded and crashed over Lockerbie, Scotland. All 243 passengers and 16 crew members were killed as well as 11 Lockerbie residents.

Policemen stand near the wreckage of the 747 Pan Am airliner that exploded over and crashed onto Lockerbie, Scotland, Dec. 22, 1988. 

The scene of devastation caused by the crash of a 747 Pan Am Jumbo jet into Lockerbie, Scotland on Dec. 22, 1988.

Convicted Lockerbie bomber Abdelbaset Ali Mohmet al-Megrahi is escorted by security officers in Tripoli, February 18, 1992. Al-Megrahi, who was serving life with a minimum term of 27 years over the downing of Pan Am Flight 103, was freed from a British jail on compassionate grounds in 2009 owing to his prostate cancer.

A member of the public pays her respects to the people who died in the Lockerbie Air Disaster, in the Garden of Remembrance, at Dryfesdale Cemetery in Lockerbie, Scotland, Dec. 20, 1998, to mark the 10th anniversary of the bombing of the airliner. 

Dan Cohen holds up a picture of his daughter Theodora, who was killed in the bombing of Pan Am Flight 103 over Lockerbie, Scotland, while speaking to the press outside the U.S. State Department, in Washington D.C., March 12, 2003. 

Pan Am Flight 103 family members met with State Department officials over a tentative agreement with Libya over the airline bombing. 

Libya agreed to take some responsibility for the 1988 Lockerbie bombing and pay billions of dollars in compensation to the families of the victims, U.S. officials said. 

A bagpiper plays during a ceremony for Pan Am Flight 103 victims at Arlington National Cemetery, in Arlington Va., Dec. 21, 2006. 

The reconstructed remains of Pan Am Flight 103 lie in a warehouse in Farnborough, England, Jan. 15, 2008. 

The Air Accident Investigation Branch have housed the remains of the Boeing 747 for the past 25 years. 

Damage to the fuselage of Pan Am Flight 103 shows where the initial blast took place, in Farnborough, England, Jan. 15, 2008. 

The reconstructed remains of the upper deck section of Pan Am Flight 103 lie in a warehouse in Farnborough, England, Jan. 15, 2008.

The reconstructed remains of the upper deck section of Pan Am Flight 103 lie in a warehouse in Farnborough, England, Jan. 15, 2008.

Libyan newspapers' front-page stories on freed Lockerbie bomber Abdelbaset Ali Mohmet al-Megrahi's return to Libya are displayed at a stall in Tripoli on August 22, 2009. 

Libya ignored Western fury at his hero's welcome and poured oil on the fire by accusing Britain of seeking commercial advantage. Megrahi is the only person found guilty of involvement in the deadly December 1988 bombing of Pan Am Flight 103 over the Scottish town of Lockerbie. 

After a hospital stay, al-Megrahi resided in Tripoli until his death on May 20, 2012.

A woman reads the names of those who were killed in the Lockerbie air disaster on the 25th anniversary of the tragedy, at the memorial wall in Dryfesdale cemetery on December 21, 2013 in Lockerbie, Scotland. 

Tributes to those killed in the Pan Am 103 air disaster sit next to the memorial wall in Dryfesdale cemetery on the day of the 25th anniversary of the disaster on December 21, 2013, in Lockerbie, Scotland. 

A handwritten card is seen on a wreath laid by the main memorial stone, in memory of a victim of the Pan Am Flight 103 bombing, in the garden of remembrance at Dryfesdale Cemetery, near Lockerbie, Scotland. Saturday Dec. 21, 2013. 

Lockerbie high street on the morning of the 25th anniversary of the air disaster.

In October 2015 Scottish and U.S. authorities announced that two Libyans had been identified as suspects in the bombing: Mohammed Abouajela Masud (a former agent of Col. Muammar Qaddafi's secret police) and Abdullah al-Senussi (the former Libyan intelligence chief). Both were imprisoned after the fall of Qaddafi.