Ghozlan’s phone rings. When he hangs up, he tells me of two unidentified Muslim men who have swept into a Jewish school in Paris’s well-heeled 16th Arrondissement. (Earlier that week, there had been an incident at another Jewish school, in the 11th Arrondissement, an area of professionals, politicians, and writers.) “How did these thugs get into the school?” Ghozlan asks. “They walked around as if they were staking it out.” The school in the 16th was evacuated and the bomb squad deployed. None of this will appear in the press, Ghozlan says. There is a fear in the schools that they will lose more students.

Ghozlan’s voice is the first thing that commands attention—his inflection is almost musical. A part of Ghozlan’s celebrity in the banlieues is his reputation as a former bandleader who played three instruments and oversaw orchestras that worked the Jewish-wedding and Bar Mitzvah circuit in Paris, advertising “Groove, Funck, Hassidiques, Israélien … Oriental.” He learned his limited English by lip-synching to Gloria Gaynor’s “I Will Survive.”

Like 70 percent of France’s Jewish population, Ghozlan is Sephardic, part of the group from North Africa called pieds-noirs (“black feet”). He lived in the Algerian city of Constantine until 1962, when, at age 20, he fled the country with his family in the wake of the Algerian war, taking with him just “a sandwich and a suitcase,” a commonly used pied-noir expression. With his wife, Monique, a petite kindergarten teacher he met when they were both in a Jewish youth group in Algeria, he lived in the house in Le Blanc-Mesnil. There were bedrooms for his three daughters and one son, and his mother, who never missed an episode of NYPD Blue. When I first met Ghozlan, he struck me as a Sephardic Columbo. Early in his police career, he managed to negotiate order in a part of the banlieues that was so violent it was nicknamed Chicago. His method was to offer judo classes to the immigrant populations—many of which spoke Arabic, as Ghozlan does. He was assigned to take care of juvenile offenders, who seemed to respond to his direct style and lack of hyperbole, which he had learned, he told me, from his father, a former chief of detectives in Constantine.

Ghozlan made his counterterrorism reputation when the synagogue on the Rue Copernic was bombed in 1980, an attack that killed 4 people and injured more than 40. Ghozlan learned that the perpetrators were Palestinian sympathizers, not the neo-Nazis the police first suspected. He was made special commissioner to investigate the next major anti-Semitic attack, on Chez Jo Goldenberg, a landmark Jewish restaurant in the Marais, where 6 people, including two Americans, were killed, and another 22 wounded, in 1982. Ghozlan’s police career—always running alongside his Bar Mitzvah shows—eventually brought him to head the department in Aulnay-sous-Bois, in Seine-Saint-Denis. He retired in 1998 and in 2000 started the B.N.V.C.A., finding himself almost alone in his fight to protect the Jews of the banlieues.

Ghozlan has been awarded the Légion d’Honneur, France’s highest tribute. But his urgency has always made him an outlier, an annoyance to the assimilation-conscious, largely secular Jewish establishment concentrated in Paris’s preferred arrondissements, who still view him as a publicity hound from the banlieues, a Jew who does not know when not to react. However noble Ghozlan’s motives, he makes a nuisance of himself with his incessant press releases, I was told a decade ago. That sentiment hasn’t changed in some quarters.

When I originally met Ghozlan, he railed that his jerry-rigged detective agency had to deal with a rigid French justice system. To register a hate crime in France—which comes with a higher level of punishment than an ordinary crime—he would have to appear in front of a magistrate, who was generally loath to call the beating of a rabbi in the Métro an act of anti-Semitism. For them, Ghozlan said, it was a “simple assault,” usually committed by an unemployed French Muslim acting out of frustration. This enraged Ghozlan. “I wanted to start a Jewish defense force,” Ghozlan told me. Judge after judge told him, “There is no anti-Semitism charge applicable unless someone dies.” The party line of the Establishment Jewish organizations in Paris was always “Sammy, stop rocking the boat.” Back then, even David de Rothschild, the banker, told The**Jerusalem Post that the wave of attacks was likely coming from “neo-Nazis, a hostile, aggressive, antisemitic, right-wing population … ” He soon changed his mind.

Foreigners Again

Twelve years later. It feels like an eye-of-the-storm moment in Paris, as the government of François Hollande tries to restore calm after last summer’s riots and the January terror attacks, amid a faltering economy and plunging euro. When I landed, in March, the rise of Marine Le Pen, the leader of the right-wing National Front, was in the headlines, as Paris was still struggling to recover from the terrorist attacks of January. Mounds of flowers and posters could be seen on the streets. There were swirls of tourists at the Louvre, as always, but there were more soldiers with automatic weapons at every Jewish school and institution, even in the dining room of a Rothschild-foundation nursing home. In the lobby of the synagogue on Rue Copernic—the one damaged by the bomb in 1980—schoolchildren walked in proximity to machine guns. The optics were unnerving.