From Zenit:
Authorities wasted no time in identifying a suspect. Joël Vigoureux, a man in his late 30s with a long history of setting fire to Catholic churches, was apprehended shortly after the blaze. Vigoureux had only recently been released from prison after serving time for a series of arson attacks on ten churches across northern France. Since his release, he had resumed his pattern of destruction, making him the prime suspect in the Saint-Omer fire. Vigoureux’s motivations are rooted in a personal vendetta against the Catholic Church. During his previous trial, he claimed to target churches because he believed that “all priests are pedophiles.” His troubling past, marked by deep-seated resentment and repeated offenses, raises serious concerns about the effectiveness of his judicial supervision and psychological treatment, which clearly failed to prevent further attacks.
French Catholic church set on fire: offender had set fire to 10 churches in France | ZENIT – English