The terrorist attack by masked gunmen on the newspaper, Charlie Hebdo, left 12 people dead - including the top editor, prominent cartoonists and police officers - and was among the deadliest in postwar France. The killers escaped, traumatizing the city and sending shock waves through Europe and beyond. (Video of Gunmen Shooting Man on Pavement)
Officials said late Wednesday that the suspects had been identified and that two were brothers. They were identified as Said and Cherif Kouachi, 32 and 34, and Hamyd Mourad, 18. French news reports said the brothers, known to intelligence services, had been born in Paris, raising the prospect that homegrown Muslim extremists were responsible. (See the pictures here)
Early Thursday, a spokeswoman for the Paris prosecutor said that Mourad had walked into a police station in Charleville-Mezieres, about 145 miles northeast of Paris, and surrendered.
"He introduced himself and was put in custody," said the spokeswoman, Agnes Thibault-Lecuivre.
The assault threatened to deepen the distrust of France's large Muslim population, coming at a time when Islamic radicalism has become a central concern of security officials across Europe. Within the space of a few minutes, the assault also crystallized the culture clash between religious extremism and the West's devotion to free expression. Spontaneous rallies expressing support for Charlie Hebdo sprung up later in the day in Paris, throughout Europe and in Union Square in New York.
Officials and witnesses said at least two gunmen carried out the attack with assault weapons and military-style precision.
President Francois Hollande of France called it a display of extraordinary "barbarism" that was "without a doubt" an act of terrorism. He declared Thursday a national day of mourning.
He also raised the nationwide terror alert to its highest status, saying several terrorist attacks had been thwarted in recent weeks as security officials here and elsewhere in Europe have grown increasingly wary of the return of young citizens from Syria and Iraq where they went to wage jihad.
French authorities put some schools on lockdown for the day, and added security at houses of worship, news media offices and transportation centers, and conducted random searches on the Paris Metro. (France Puts Paris on Highest Alert Status After Shooting)
The Paris prosecutor, Francois Molins, said according to witnesses, the attackers had screamed "Allahu akbar!" or "God is great" during the attack, which the police characterized as a "slaughter." (Paris Attackers Shouted 'We Have Avenged the Prophet': Police)
Corinne Rey, a cartoonist known as "Coco," who was at the newspaper office during the attack, told Le Monde that the attackers spoke fluent French and had said they were part of al-Qaida.
An amateur video of the assailants' subsequent gunfight with the police, showed the men shouting, "We have avenged the Prophet Muhammad. We have killed Charlie Hebdo!" The video, the source of which could not be verified, also showed the gunmen killing a police officer as he lay wounded on a nearby street.
The victims at Charlie Hebdo included some of the country's most revered and iconoclastic cartoonists. The weekly's editorial director, Stephane Charbonnier, had already been receiving light police protection after earlier threats, the police and Molins said. An officer assigned to guard the newspaper's offices and its top editor was among the victims.
Spontaneous vigils of hundreds and thousands formed in other cities around France and elsewhere in Europe.
Molin, the prosecutor, said that two men armed with AK-47 rifles and wearing black masks, had forced their way into the weekly's offices about 11:30 a.m., firing at people in the lobby, before making their way to the newsroom on the second floor, interrupting a news meeting and firing at the assembled journalists.
The attackers then fled outside, where they clashed three times with police, shooting one officer as he lay on the ground on a nearby street. They then fled in a black Citroen, and headed north on the right bank of Paris. During their escape, prosecutors said, they crashed into another car and injured its female driver, before robbing and abducting a bystander.
Police said the precision with which the assailants handled their weapons suggested that they had received military training. During the attack, which police said lasted a matter of minutes, several journalists hid under their desks or went to hide on the roof, witnesses said.
Meziani Zina, 32, who works at the reception of an employment center across from the building, said she heard several loud shots ringing from the weekly's headquarters.
One journalist, who was at the weekly during the attack and asked that her name not be used, texted a friend after the shooting: "I'm alive. There is death all around me. Yes, I am there. The jihadists spared me."
Treasured by many, hated by some, and indiscriminate in its offensiveness, Charlie Hebdo has long reveled in provoking.
In 2011, the office of the weekly was badly damaged by a firebomb after it published a spoof issue "guest edited" by the Prophet Muhammad to salute the victory of an Islamist party in Tunisian elections. It had announced plans to publish a special issue renamed "Charia Hebdo," a play on the word in French for Shariah law.
Police said the dead included four celebrated cartoonists at the weekly, including Charbonnier, known as "Charb," Jean Cabut, Georges Wolinski and Bernard Verlhac.
Charbonnier stoked controversy and earned the ire of the Muslim community in 2006, when he republished satirical cartoons of the Prophet Muhammad that had been published in a Danish newspaper, Jyllands-Posten. His last cartoon for Charlie Hebdo featured an armed man who appeared to be a Muslim fighter with a headline that read: "Still no attacks in France. Wait! We have until the end of January to give our best wishes."
President Barack Obama issued a statement condemning the attack. "Time and again, the French people have stood up for the universal values that generations of our people have defended," he said. "France, and the great city of Paris where this outrageous attack took place, offer the world a timeless example that will endure well beyond the hateful vision of these killers. We are in touch with French officials, and I have directed my administration to provide any assistance needed to help bring these terrorists to justice."