PARIS — French investigators tracked down the alleged ringleader of last week's Paris bloodshed after receiving a startling tipoff: The Islamic militant wasn't in Syria but in Europe, plotting yet another attack. A discarded cellphone found near a bloodied concert hall led them to his cousin, and then to a suburban Paris apartment where both died in a hail of bullets and explosions.
As a manhunt intensified Thursday for a fugitive connected to the carnage, details emerged about the intelligence operation that allowed authorities to zero in on Abdelhamid Abaaoud, the Belgian-Moroccan extremist they say orchestrated the attacks in Paris and four plots thwarted earlier this year.
The narrative provided by French officials raised questions about how a wanted militant suspected of involvement in multiple plots could slip into Europe undetected.
Investigators quickly identified Abaaoud as the architect of the deadly attacks in Paris, but they believed he had coordinated the assaults against a soccer stadium, cafes and a rock concert from the battlefields of Syria.
That situation changed profoundly on Monday, when France received a tip from a non-European country that Abaaoud had slipped into Europe through Greece, Interior Minister Bernard Cazeneuve said.
"It was a big surprise when the intelligence came in," said a police official, speaking on condition of anonymity because the information was sensitive. "There were many people who didn't take it seriously, but effectively it was confirmed."
As it turned out, not only was Abaaoud in Europe, but right in front of the noses of French investigators, a 15-minute walk from the Stade de France stadium where three suicide bombers had blown themselves up during the Nov. 13 attacks that killed 129 people and wounded hundreds.
"We have strong reason to believe that this cell was about to commit massive terror attacks in France," Prime Minister Manuel Valls said Thursday, speaking on public broadcaster France 2.