SAINT-ETIENNE-DU-ROUVRAY, France (REUTERS) - Adel Kermiche was an attention-seeking child whose behavioural problems frequently led him to a psychiatric hospital and later a specialist school. He died a coldblooded killer who slit the throat of an elderly French priest in the name of Islamic State in Iraq and Syria (ISIS).
The son of a working class Franco-Algerian family living just outside the Normandy city of Rouen, the teenager flipped between model student and aggressor as a youngster. He blipped on the radar of security services in early 2015, when he made his first failed bid to reach Syria.
Kermiche burst into a church on the outskirts of Rouen during morning mass on Tuesday with another teenage Islamic militant and killed the 85-year-old father at the altar, chanting in Arabic, before they were both shot dead by police.
"He was a loner. He was a troubled soul, he was all alone in his head," said a neighbour of the Kermiche family house in a leafy Rouen suburb where the 19-year-old was forced to live under a court surveillance order. "All he would talk about was Syria."
A judicial source said Kermiche received regular psycho-therapy and medication between the ages of six and 13, at which point he was sent to school for pupils with behavioural problems.
What role Kermiche's troubled background played in his conversion to a killer is not clear. Kermiche's radicalisation, however, was swift.
His mother told Swiss newspaper La Tribune de Geneve last year that Kermiche became "bewitched" by hardline Islamic ideology after militants attacked the satirical Charlie Hebdo magazine in Paris in January, 2015. Two months later, he made his first attempt to reach Syria to become a militant.
Investigators are digging into the relationship between Kermiche and Abdel-Malik Nabir Petitjean, who lived in a French alpine town 700km away from Kermiche, and how the two communicated before staging their attack.
Kermiche frequently communicated with scores of followers on Telegram, a private communication channel whose encrypted message system makes tracking chatter difficult for intelligence agencies.
In audio posts obtained by L'Express magazine and whose content was confirmed to Reuters by a police source, Kermiche told about 200 followers that going to Syria was no longer an option because of border controls, and urged them to launch attacks on French soil instead.
"You get a knife, go to a church, spread carnage, boom. You cut off two or three heads and you're done," he said.
Just hours before the attack, he posted another message saying "Download what's coming next and share it widely!!!!". He last logged onto the app at 9.46am from inside the Saint-Etienne church, but he failed to post any video of the killing.
The attack has raised questions over how security services can clamp down on the proliferation of online videos urging disillusioned Muslims to take up arms for ISIS and other groups, as well as channels of communication on social media.
A Telegram spokesman said its public content was moderated on a 24/7 basis and "as a result ISIS channels usually go down within less than a day, mostly within hours."
But he said Telegram, like other encrypted messengers, did not have access to closed chats and communities and could not moderate their content.
In November, Telegram said it had identified and blocked 78 ISIS-related broadcast channels in 12 languages on its site.
Conservative politicians have been scathing of President Francois Hollande's security record, branding him soft on suspected militants. Kermiche himself was supposedly under close surveillance and wore an electronic tag.
Friends said he would routinely try to indoctrinate them.
"Each time we said something to him, he would come back at us with a verse from the Quran," said 18-year-old Redwan, a school friend of Kermiche. "He would tell us we had to fight for our Muslim brothers, that France was a country of infidels."
He tried reaching Syria twice. The first time, he was intercepted in Germany in March, 2015, using his brother's identity card after his family reported him missing.
Sent back to France, he was charged with terrorism offences but released on bail ahead of a trial. He was banned from leaving his local area, but two months later he slipped away and was detained in Turkey, this time travelling on his cousin's ID card.
France held Kermiche in detention until March this year when a judge ruled him fit for release under strict supervision, despite the protests of prosecutors. Forced to surrender his passport and fitted with an electronic tag, Kermiche was restricted to leaving his parents' home for a few hours a day.
Court documents first published by Le Monde and confirmed to Reuters by a judicial source showed he told the judge he regretted his attempts to leave for Syria.
"I'm a Muslim who believes in mercy, in doing good, I'm not an extremist," he told the judge. "I want to get back my life, see my friends, get married."
Marc Trevidic - a former anti-terrorism judge who placed Kermiche under investigation but was not involved in the decision to release him - said in a interview with L'Express that he had struck him as determined and arrogant.
"His case is typical of these individuals desperate to go, but that justice manages to keep here. So they get their revenge by doing jihad in France," he was quoted as saying.
In his quiet neighbourhood of Saint-Etienne-du-Rouvray, local people said he was still openly discussing ways to escape again.
"My son bumped into him in March at a bus stop. He told him he had been pushed back from Turkey but would try again, he was being manipulated," Sebastien, the father of Kermiche's former school friend told Reuters at the local grocer.
"As a kid, he always needed to show off. He was hyperactive, very nervous, he created trouble to get attention," he said.
Local residents said Kermiche did not come from a dysfunctional family, with a mother who taught in a local high school and a sister who trained as a doctor, adding that the wider Muslim community was well integrated in the area.
At the local mosque, Mohammed Karabila, head of the regional Muslim council, pointed at a small wall separating the mosque from Saint-Etienne's second church as a demonstration of the harmony between the town's religious communities. Kermiche, he said, was unknown at the mosque.
"We would have liked him to come to the mosque," Karabila said.
"But today, these kids' mosque is Google; it's the Internet."