Salah Abdeslam, 26, a Belgian-born French national, is believed to have played a key logistical role in the November 13, 2015 carnage in Paris which left 130 dead. He fled across the border to Belgium hours after the massacre.
He and his brother Brahim, who blew himself up in Paris, managed a bar together in the Molenbeek area of Brussels, that was shut down by authorities just weeks before the massacre.
Friends and locals said they were fond of the joint and that there was no sign they were radical Islamists with murderous intent.
Between 2009 and 2011, Abdeslam worked as a mechanic for STIB, the Belgian state railway.
The Abdeslam family is of Moroccan origin and hails from the run-down Brussels quarter of Molenbeek which is home to a large immigrant community.
Before the attack
In August 2015, Abdeslam and another suspected Islamic State militant caught a ferry in Italy and headed to Greece as “free citizens, not sought-after terrorists,” according to Italian Interior Minister Angelino Alfano.
Early in September 2015, after traveling the length of Italy on his way home to Belgium, Abdeslam took a rental car twice to Budapest, according to Belgium’s federal prosecutor.
In mid-September last year, Abdeslam was stopped at a checkpoint on the Austrian border in a rental Mercedes, accompanied by two people with Belgian ID cards that later turned out to be fake, according to the Belgian federal prosecutor. He was waved on through.
In October, Abdeslam bought detonators from a pyrotechnics shop outside Paris.
Early November, he rented a Volkswagen Polo used in the attacks at Astral Rent Car in the Brussels suburb of Etterbeek.
Video surveillance showed Abdeslam and fellow Molenbeek resident, Mohamed Abrini, together in a Renault Clio buying gas in the Oise region, north of Paris.
On November 12, Abdeslam’s one-week rental began for two studios in Appart City Hotel in the Paris suburb of Alfortville. He and Abrini were spotted together that day leaving Brussels.
Role in Paris attack
He is thought to have fled to Brussels the day after the Paris attacks after refusing to blow himself up and believed to have holed up in a flat for at least three weeks evading detection by the Belgian police.
He slipped past three police checks in France as he fled to Belgium just hours after the terror assaults, a source close to the probe said in December.
Investigators believe Abdeslam hired one of the cars used in the attacks and then used it to drive suicide bombers to the Stade de France with the task to then blow himself up.
But he apparently backed out, and an explosives-filled suicide vest was later found in Paris in a region that mobile phone signals indicated he had been in.
The ringleader of the attacks, IS member Abdelhamid Abaaoud, was also from Brussels. He was killed in a raid in Paris in November.
Abdeslam is a childhood friend of Abaaoud.
Arrested last week
Salah Abdeslam was arrested in Belgium’s capital after four months at large on March 18, 2016. He was arrested in a major police operation in the Brussels neighborhood of Molenbeek.
The capture of Abdeslam came after Belgian authorities found his fingerprints in an apartment raided earlier in another Brussels neighborhood.
A string of explosions rocked Brussels airport and a city metro station on Tuesday, killing at least 21 people, days after the dramatic arrest in Brussels of Salah Abdeslam.