French officials tell the AP that the man who organized the Paris attacks was a Belgian jihadi who claims he was almost captured but ultimately let go during a manhunt earlier this year.

The man, Abdelhamid Abaaoud, reportedly attended one of Brussels’ most prestigious high schools before he adopted the radical view of Islam that culminated in the deaths of hundreds of people Friday.

Abaaoud is certainly known to officials—he’s been tied to several thwarted attacks including the Paris high-speed train attack, an attack against a French church, and a plot to shoot up French police.

What’s more, police may have had him in custody before accidentally releasing him during a manhunt in Belgium earlier this year. Via the AP:

Belgian authorities suspect him of also helping organize and finance a terror cell in the eastern city of Verviers that was broken up in an armed police raid on Jan. 15, in which two of his presumed accomplices were killed. The following month, Abaaoud was quoted by the Islamic State group’s English-language magazine, Dabiq, as saying that he had secretly returned to Belgium to lead the terror cell and then escaped to Syria in the aftermath of the raid despite having his picture broadcast across the news. “I was even stopped by an officer who contemplated me so as to compare me to the picture, but he let me go, as he did not see the resemblance!” Abaaoud boasted.

And other jihadists tied to Friday’s plot were also reportedly known to police. According to the AP, one suicide bomber who blew himself up at the Bataclan music hall was a 28-year-old Frenchman charged with terrorism in 2012. He “had been placed under judicial supervision but dropped off the radar and was the subject of an international arrest warrant.”

Another suspected bomber, Omar Ismail Mostefai, was reportedly identified by Turkish authorities as a terrorist risk both in 2014 and 2015. Despite notifying French authorities, Turkey says it received no response until after the attacks Friday. The Paris prosecutor’s office tells the AP “Mostefai had been flagged as having ties to Islamic extremism five years ago.”

In the meantime, authorities are taking coordinated steps to round up others connected to the plot: some 104 people are reportedly under house arrest after police executed early morning anti-terrorism raids at more than 150 locations.

And at least three people were reportedly arrested in an impoverished Brussels town called Molenbeek, where two explosions were reported amidst an ongoing manhunt for a man named Salah Abdeslam, who police believe helped carry out the attacks Friday.