The unidentified suspect, 63, was a crime reporter for the Nouvelle Republic but turned from writing about it to making his own headlines Friday when he held up a department store, Radio France Internationale said.
Police said the man disguised himself with a mustache, wig and gloves before entering the store and pointing a black revolver at a clerk, demanding cash. Police had staked out the store because he targeted it once before.
In all, police said the suspect, who may have conducted several other robberies, made off with about $12,300 before he was caught.
The man told police he was coming out of a divorce and struggling to pay for his son's college tuition.