Adel Kermiche and Abdel Malik Petitjean, the 19-year-olds who slit the throat of Fr Jacques Hamel (86) while he celebrated Mass last Tuesday, first contacted each other only four days before the murder.
The apprentice jihadists, both of whom had tried and failed to reach Syria, communicated via the encrypted application Telegram, which Islamic State urges its followers to use.
The young men lived 700km apart; Kermiche in Normandy, Petitjean in Savoie. The day after their first contact on Telegram, Petitjean left his mother’s house in Aix-les-Bains and travelled to Saint-Étienne-du- Rouvray, where a court had ordered Kermiche to live with his parents and wear an electronic bracelet.
Petitjean spent a first night in the Kermiche home, then slept in a tent in the garden. His identity card was found in the house after the assailants were shot dead by French commandos outside the church in Saint-Étienne-du-Rouvray.
Investigators suspect that someone in Islamic State (also known as Isis) introduced the two young men.
Attention has focused on Adel Bouaoun, who travelled to Syria in May 2015 using Kermiche's identity papers. Bouaoun's 16-year-old brother was detained and then released after the church killing, but remains under surveillance.
Kermiche revealed his plans in chilling detail to a private chat group via Telegram.
"If you want to go to [Syria] it's complicated because the borders are closed," he said, as quoted by L'Express, which viewed the video. "So you may as well attack here. You take a knife. You go to a church. You make a carnage. You cut off two or three heads and you're done."
The Telegram application was invented by Russian brothers Nikolai and Pavel Durov. It provides more complex options than WhatsApp or Facebook Messenger, which are also favoured by jihadists.
There are 100 million Telegram users throughout the world, according to Le Monde.
Pavel Durov has fled
and became a citizen of the small Caribbean islands St Kitts and Nevis. After the November 13th, 2015 attacks in Paris, he said that “the right to a private life is more important than our fear of seeing bad things happen, like terrorism”.
Telegram nonetheless shut down 78 accounts and “official” channels belonging to Islamic State last February.
Police had been in possession of Petitjean’s profession of allegiance to Islamic State, which he posted via Telegram, for four days before the murder in the church, but were unable to identify its author.
In the video, Petitjean exhorted “all Muslim brothers to strike this country [France] and strike the allies of the [anti-Isis] coalition.”
Addressing himself to French president François Hollande and prime minister Manuel Valls, Petitjean said: "We are going to destroy your country and raise our banner."
Petitjean was described by those who knew him in the French alps as "polite" and "serious". According to Le Figaro, he was employed as a baggage handler at Chambéry Airport until April of this year.
A foreign intelligence service brought Petitjean's video to the attention of French authorities. His name had been placed on the "S" (for "security") watchlist for radicalised Muslims in France on June 29th, after he tried to reach Syria but was turned back in Turkey.
Incredibly, police had no photograph of Petitjean, which could have enabled them to connect his name with the Telegram video before Father Jacques was murdered.
Petitjean’s cousin, identified as Farid K (30), was arrested on Sunday night on suspicion of belonging to a terrorist group. “It appears at this stage of the investigations that Farid K had perfect knowledge, if not of the place and precise date, of the imminence of a plan for violent action by his cousin,” said a statement from the prosecutor.
Also charged was 20-year- old Jean-Philippe J, for attempting to reach Syria via Turkey with Petitjean on June 10th.
Another man, identified as Omar C (19), was arrested on July 24th and charged in a separate investigation on July 29th. Investigators found Petitjean’s profession video on Omar C’s smartphone.
A Syrian refugee who was arrested in the Allier department of central France last Thursday has been released. Police had found a photocopy of his passport in the Kermiche home.
Fr Jacques’s funeral will take place at 2pm today in Rouen Cathedral.
The French Council of the Muslim Faith had called on Muslims to attend Catholic Mass on Sunday, “to express anew to our Christian brothers the solidarity and compassion of the Muslims of France”.
About 100 Muslims out of 2,000 Mass-goers attended to Rouen Cathedral on Sunday. Only a handful of Muslims attended Catholic services elsewhere.
In an open letter published by the Journal du Dimanche, the prime minister, Valls, warned that "if Islam does not help the Republic to fight those who question public liberties, it will be more and more difficult for the Republic to guarantee the freedom to exercise [their] faith.
“There must be a massive, powerful commitment, first of all by Muslims,” Valls wrote. “I call on them to act within their families and within their neighbourhoods.”