The Anti-Defamation League on Thursday will host a memorial for a 23-year-old Jewish Parisian, Ilan Halimi, who was brutally murdered by a gang led by Muslim immigrants.

The associate national director of the Anti-Defamation League, Kenneth Jacobson, who will speak at the event, told The New York Sun in a telephone interview that the primary purpose of the service was “to stand in solidarity and sympathy with the family and Jewish community in France.”

Peter Yarrow of Peter, Paul, and Mary fame will sing at the event, as will Cantor Michael Kakon. An official at the French Consulate is scheduled to speak.

The French government declared the murder a hate crime, and thousands marched through Paris on Sunday to protest anti-Semitism.

“Everyone in France, Jews and non-Jews alike, is shocked and outraged by the heinous murder of Ilan Halimi. As President Chirac expressed in 2004, ‘An attack on a Jew is an attack on France,'” the French Consulate’s spokesman, Yann Battefort, said via e-mail.

Mr. Jacobson applauded the French reaction to the murder, though he said there was more to do to combat the reemergence of anti-Semitism in the country, including increased education efforts and urging leaders in the Muslim community to issue public statements decrying bigotry.

He said the crime was especially disturbing because it combined elements of what he called “the old anti-Semitism” – demonizing Jews as rich and hateful – with the new, which arises out of Muslim minorities in Western countries and often includes radical opposition to Israel.

Halimi was kidnapped on January 20 and held for ransom because, the criminals said, “Jews have money.” On February 11, Mr. Halimi was found brutally butchered and died on the way to the hospital.

Mr. Battefort said 11 of the 13 suspects have been apprehended and would be tried for anti-Semitic hate crimes. The gang leader fled to his country of origin, the Ivory Coast, where he was arrested. French officials have requested his extradition.