Four alleged accomplices in the murder of an 85-year-old French priest go on trial in Paris on Monday after years of investigations into the killing, carried out while the the victim was celebrating Mass in the north-western city of Rouen.
Father Jacques Hamel had his throat slit at the foot of the altar while celebrating Mass on 26 July 2016, at his church in Saint-Etienne-du-Rouvray, a working-class suburb of Rouen.
The two 19-year-old assailants, Adel Kermiche and Abdel-Malik Petitjean, seriously injured one of the worshippers they took hostage before themselves being shot and killed by police as they tried to leave the church.
The pair claimed in a video to be members of the Islamic State terror organisation, which later described them as "soldiers" retaliating for France's fight against jihadists in Syria and Iraq.
Father Hamel's murder came in the wake of a series of jihadist attacks that began with a massacre at the satirical newspaper Charlie Hebdo in January 2015 and the so-called Bataclan attacks later that year.
The priest's killing raised questions about the ability of French intelligence agencies to prevent such attacks, since Kermiche was wearing an electronic bracelet at the time.
Prosecutors say that the four accused knew about the attackers' plan, with one of them travelling with Petitjean to Turkey in an attempt to reach Syria, just weeks before the attack.
They have denied the charges of conspiracy in a terrorist crime. Their lawyers have claimed that the men are being used as "scapegoats".
'Pounce on the unbelievers!'
One of the accused, Rachid Kassim, a Frenchman who became a key IS recruiter and is the alleged instigator of the attack, has been charged with complicity in the killing by helping to choose the target and providing advice.
"Pounce on the infidels like a hungry lion pounces on its prey," Kassim told them in audio and social media conversations discovered by investigators.
Police also believe Kassim was behind the chilling murder of a police officer and his companion in front of their three-year-old son in Magnanville, a Paris suburb, just a few weeks before Hamel's murder.
Kassim is believed to have been killed in a coalition airstrike near Mosul in 2017, Iraq, where he lived, but is being tried in absentia since the death has not been confirmed.
Despite the absence of the main culprits, Father Hamel's relatives and the other victims are hoping to learn how the young men came to embrace the extremist ideology that led to the attack.
Praise from Pope Francis
Catholic Church officials have launched the process to seek beatification for Hamel, a first step to canonisation or sainthood, which is currently being examined by the Vatican.
Roman Catholic leader, Pope Francis, who approved a fast-track process for Hamel, called him a "martyr," saying he had died for his faith, which means there is no requirement of a proof of miracles in his case.