The 29-year-old gunman who killed three people at a Christmas market in Strasbourg before being shot dead by police after a two-day manhunt was a career criminal with convictions in France and several other European countries.
Cherif Chekatt had been convicted of crimes including violence and robbery and was added to a watchlist of possible extremists while in prison in France in 2015, by which point he was described by authorities as having become radicalised.
He had since been monitored by France's domestic intelligence agency, the DGSI, which monitors thousands of suspected extremists in France.
A photograph released by French authorities showed a man with dark, deep-set eyes, black hair, a short beard and a mark on his forehead.
One source said that a poster of Al Qaeda leader Osama bin Laden had been found in his cell in 2008.
Neighbours, however, described a man who was known in the area due to his criminal record, but kept a low profile, only venturing downstairs for a coffee and baguette.
"He wasn't totally into Islam," one neighbour named Zach, 22, told AFP, describing Chekatt as "discreet, not a thug", who lived alone in a small apartment in a dilapidated building in the same area as his parents.
"His family has lived around here for a while, but he lived on his own nearby," he said.
Chekatt had been sentenced 27 times -- mostly in France, but also in Germany, Switzerland and Luxembourg, which are all easily reached from Strasbourg.
He was first sentenced at the age of 13 and was described by French Interior Minister Christophe Castaner as having exhibited criminal behaviour since the age of 10.
Described by one source as being aggressive at times, Chekatt was, however, said to be at the low end of the spectrum in terms of his radicalism, showing no hint of carrying out an attack.
In prison, the man who shouted "Allahu akbar" (God is greatest) during Tuesday's attack was described as practising a radical form of Islam.
And although the propaganda wing of the Islamic State group claimed responsibility for Tuesday's attack and described Chekatt as "one of the soldiers of the Islamic State", the source said there was no sign he had any established links with Syria.
Chekatt was "a familiar composite portrait of today's jihadist", Anne Giudicelli, Director of the consulting firm Terrorisc, told AFP.
"He has ticked all the boxes of the profiles seen before."
At the nine-storey concrete block where Chekatt's name appeared on a letterbox, one local, Bemba N'diaye, 37, painted a grim picture of the area.
"People there are very isolated," N'diaye told AFP.
"It's a building for desperate people. No one wants to live there."