The appeal trial opened in Paris on Monday for two men suspected of helping the gunmen who stormed the Charlie Hebdo satirical weekly and a Jewish supermarket in January 2015, the first of a wave of Islamist terror attacks that have rocked France in recent years.
Twelve people were massacred at Charlie Hebdo's Paris offices by the brothers Said and Cherif Kouachi, who said they were acting on behalf of Al-Qaeda to avenge the paper's decision to publish cartoons of the Prophet Mohammed.
A day later, Amedy Coulibaly killed a 27-year-old police officer during a traffic check outside Paris, before killing four Jewish men during a hostage-taking at the Hyper Cacher supermarket on January 9, claiming to act in the name of the Islamic State group.
All three were killed by police, and in December 2020 a French court convicted 14 people of helping to carry out the attacks.
Two men who were given the heaviest sentences appealed, notably Ali Riza Polat, who received a 30-year prison term on charges he helped find weapons for the killers.
Both he and Amar Ramdani, accused of conspiring with the attackers, deny the charges, and want the court to examine documents they say were neglected during the inquiry.
"This trial is the last chance to correct the errors of a justice system overwhelmed by the scope of these attacks, and return to reason with regards to the exact role of M Polat, a common criminal who's been wrongly accused of a role he never had," his lawyers said.
A lawyer for Charlie Hebdo, Richard Malka, dismissed the claims.
"These crimes have a purpose, they are political, ideological -- these aren't crimes carried out by barbarians or 'lone wolves' or crazy people," he said at the Paris courthouse ahead of the trial's opening.
The paper's editor Laurent "Riss" Sourisseau, injured in the attack, attended the hearing, and the widow of one of the victims carried a poster of the others killed.
'I am Charlie'
The killings signalled the start of a deadly wave of Islamist attacks around Europe, in particular the harrowing killing spree a few months later at the Bataclan concert hall and at Paris bars and cafes in November 2015.
The first Charlie Hebdo and Hyper Cacher trial was held in 2020 with 14 defendants -- some tried in their absence -- accused of helping the gunmen prepare and organise the attacks.
Jail terms ranging from four years to life were handed out for those convicted of helping the Kouachi brothers and Coulibaly, who were killed during police assaults.
The appeal court will have six weeks to weigh up the degree of responsibility of Polat and Ramdani.
Several days at the start of the trial will be given to hearing testimony from survivors of the attack and relatives of the victims.
Those shot dead in the Charlie Hebdo office included some of France's most celebrated cartoonists including Jean Cabut, known as Cabu, 76, Georges Wolinski, 80, and Stephane "Charb" Charbonnier, 47.
The massacre triggered a global outpouring of solidarity with France under the "I am Charlie" slogan.