Trans-activists want to rename the Cathedral "Our Lady of the Survivors of Child Crime."
The 28-year-old suspect was found with a loaded gun and had already been known for other offences.
The Vie et Lumière (Life and Light) evangelical church in Marseille, France was recently vandalised.
The local authorities are showing indifference and do not intend to remove them.
On Sunday, the 15th of August, a man was arrested in Agen, France, after urinating in the Church of the Sacred Heart.
There are no reports about what will happen with the culprit from now on.