In the trove of digital and handwritten materials found at bin Laden’s compound in Pakistan in May, there were numerous references to the 10-year anniversary of the attacks on New York and Washington. The material also contained various inchoate ideas about how al-Qaeda might construct a terrorist operation, according to law enforcement and intelligence officials.
“We would be paying extra attention because of the Sept. 11 anniversary alone without what was found at the bin Laden compound, but the fact that in the aftermath of his death there were documents indicating an attack on or about the anniversary — that has certainly focused our planning,” said Paul J. Browne, chief spokesman for the New York City Police Department. Because the assumption is “that New York remains on top of the terrorist target list . . . there will be a full-court press on Sept. 11 and in the days leading up to it.’’
One official who reviewed the materials said that the date became more significant to al-Qaeda mainly because bin Laden and others tracked U.S. media and noted the public’s preoccupation with Sept. 11. “Our obsession with anniversaries had an impact on him,” said a senior U.S. counterterrorism official who reviewed the bin Laden materials. “He learned over time we are particularly sensitive about particular dates.”
Increased security will also be visible in the Washington area, where, as in New York, there will be more police officers on the street, with a focus on anniversary ceremonies, airports, mass transit and athletic events.
“Everything we’ve learned and the way local police agencies have evolved over the past 10 years puts us in a very different place than we were on Sept. 11,” said D.C. Police Chief Cathy L. Lanier.
She said police have been preparing for months trying to prevent an attack and ramping up response measures if there is one.
A federal law enforcement official, who spoke on condition of anonymity because security measures are not public, said that the FBI and the Department of Homeland Security have been conducting intensified briefings with local law enforcement officials across the country for several months.
“The safety and security of the American public remains our highest priority,” DHS Secretary Janet Napolitano said in a statement Friday. “While threats remain, our nation is stronger than it was on 9/11, more prepared to confront evolving threats, and more resilient than ever before.”
John Brennan, the president’s homeland security and counterterrorism adviser, has chaired senior-level meetings on security preparations over the past four months, according to the White House.
“These senior-level reviews of our security posture will continue through the 9/11 anniversary and beyond in order to ensure the federal government remains fully prepared to take whatever steps are necessary to mitigate any potential attacks,” said White House spokesman Clark W. Stevens.
Officials said that a major concern is a “lone wolf” attack such as the one in Norway in July, when a 32-year-old man shot and killed 77 people at a political youth camp outside Oslo.
“You know, when you’ve got one person who is deranged or driven by a hateful ideology, they can do a lot of damage, and it’s a lot harder to trace those lone-wolf operators,” Obama said in a interview with CNN last month, describing the potential for such an attack as “the biggest concern we have right now.”
Obama and first lady Michelle Obama will also attend ceremonies in Pennsylvania and at the Pentagon on Sept. 11.
Det. Crystal Nosal, a spokeswoman for the Arlington County Police Department, said that officials “are taking security measures that are heightened beyond a normal day.’’
She said that the measures will be across the county and extend to a run that will pass the Pentagon on Sept. 10.
In New York, police will create what they call a frozen zone around Ground Zero, which will extend for several blocks in all directions. Only people with credentials will be able to get into the traffic-free zone, and residents wanting to return to their apartments will have to be escorted by police officers. Police snipers will be on the rooftops near the World Trade Center site, Browne said.
Browne said the overall effort is an attempt to “intercept an attack if one is coming our way and to respond to any number of threats, including the active shooters you saw in Mumbai, anything coming in over the water, chemical, biological, radiological.’’
In November 2008 in Mumbai, India’s commercial capital, a group of gunmen with Lashkar-e-Taiba, a Pakistani militant group, killed 166 people and wounded hundreds in coordinated attacks on hotels, a railroad station and a Jewish center.
Staff writer Greg Miller contributed to this report.