Soon afterwards, hundreds of refugees who had arrived in the previous days were hacked or beaten to death or blown up with hand grenades within the space of a few hours, according to survivors.
They say Ngenzi and Barahira took part in the process of separating the Tutsis from the Hutus.
Barahira, as the town’s former mayor, was said to have “exceptional influence”, his lawyer said, adding that he “went to see if he could do something to help the refugees”.
Ngenzi, accused of initial passivity before taking on an active role, is described by his lawyer as “a good mayor overwhelmed by events”.
He has been held since 2010 when he was captured in the French overseas department of Mayotte off the east coast of Africa, where he had been living under a false name.
Barahira was arrested in 2013 in the southwestern French city of Toulouse where he was living.
– ‘Time on killers’ side’ –
Gauthier’s non-profit CCPR is devoted to tracking down alleged perpetrators of the genocide who fled to France.
Likened by some to a Nazi hunter, he says his task is a race against time.
“We’re well aware that it is going to be more and more difficult to try people. More than 20 years after the genocide some witnesses contradict each other, or they’re vague… Time is on the killers’ side,” he said.
Kigali broke off ties with Paris in 2006 after a French judge issued arrest warrants against nine Rwandan officials over the assassination of Hutu president Juvenal Habyarimana.
The shooting down of the presidential plane on April 6, 1994, was blamed on the Tutsis and is considered to be the event that sparked the genocide.
The diplomatic freeze lasted for three years.
Last year, charges were thrown out against a priest, Wenceslas Munyeshyaka, the first Rwandan to be prosecuted in France in what had also been viewed by his defence as a politically motivated case.