A former hotel driver went on trial in Paris on Monday accused of complicity in Rwanda's 1994 genocide for transporting Hutu militiamen who massacred hundreds of Tutsis.
Investigators say Claude Muhayimana, also hid Tutsis at risk of death, helped some escape, fled after the genocide and gained French nationality in 2010.
Claude Muhayimana's lawyer Philippe Meilhac, said : "He is only waiting for one thing, to be able to explain himself. Today, he is in his sixties, he is a man who has had a difficult life, who is, by the circumstances, worn out, tired, and who is waiting to be able to explain himself and have his honor returned to him."
Muhayimana was arrested in France in 2014 after an investigation by Paris prosecutors specialising in crimes against humanity.
He spent a year in preventive detention before being released on probation, when he resumed his work as a road repair agent in the northern French city of Rouen.
He is accused of knowingly driving Hutu police and militiamen called the Interahamwe to carry out massacres in the western Kibuye region.
Tens of thousands of Tutsis were murdered as they sought shelter in schools, churches and hotels.
Muhayimana, who was married to a Tutsi woman at the time, has denied the charges, saying he was not in Kibuye when the massacres took place.
"He is going to fully explain himself," his lawyer Philippe Meilhac told AFP before the trial. "This is a man who has been waiting 10 years for this."
Muhayimana will be the first "ordinary" citizen to face justice having been considered "respectable all around" before the killings, said Alexandre Kiabski, a lawyer for the Collective of Civil Parties for Rwanda (CPCR), one of the plaintiffs.
He faces a life sentence if convicted.
"You know, an accomplice, he is charged with complicity. And complicity I think in law is exactly the same as if you are an author. So it's like if he's a co-author, but it's the proceedings that will determine whether or not he's guilty of that, whether or not he collaborated out of his own free will or not." Dafroza Gauthier, co-founder of the group who started the proceedings stated.
France has generally refused requests to extradite suspects to Rwanda, prompting President Paul Kagame to accuse Paris of denying Rwanda jurisdiction.
But relations between the two countries have warmed considerably since a historians' report commissioned by President Emmanuel Macron and released in March recognised France's "overwhelming" responsibilities in failing to halt the massacres.