How alarmed were New Jersey officials by reports of Muslims dancing in the streets of Jersey City and Paterson on Sept. 11, 2001, to celebrate the destruction of the World Trade Center?
They feared riots would break out and were ready to send in the National Guard and the State Police to preserve order.
But John J. Farmer Jr., then the New Jersey attorney general and the state’s chief law enforcement officer, said on Tuesday that he ordered an investigation that very day and found the reports to be bogus, more wild stories born in the stricken hours after the attacks.
Nevertheless, those ancient, false rumors were recycled as truth over the weekend by Donald J. Trump, who has folded them into his calls for the national registration of Muslims and possible closing of mosques. Speaking in Alabama, Mr. Trump said: “Hey, I watched when the World Trade Center came tumbling down. And I watched in Jersey City, N.J., where thousands and thousands of people were cheering as that building was coming down. Thousands of people were cheering.”
Reporters were unable to find any evidence for his story, but Mr. Trump stuck with it in a television interview on Sunday. “It did happen,” he said. “I saw it. It was on television.”
Few people, if any, could address the circumstances more definitively than Mr. Farmer, who went on to serve as senior counsel to the Sept. 11 commission.
In an account Mr. Farmer provided Tuesday, he described being in the state’s command center, in Liberty State Park in Jersey City, directly across the Hudson River from the burning wreckage of the trade center. The New Jersey State Police radio antenna had been on top of one of the towers, cutting off communications.
“We were forced to rely on runners for intelligence about what was happening across the river and in New Jersey,” Mr. Farmer said.
In the vacuum, rumors were flying, he said. Bombers with suicide vests were in Times Square. Saboteurs were lurking around power plants. New York City’s mayor, Rudolph W. Giuliani, was missing.
And then there was the wisp of a story that Mr. Farmer said was most disturbing of all: “That Muslims were dancing on the rooftops and in the streets of Jersey City and Paterson.”
Indeed, pockets of radical Islamists had set up in Jersey City in the past. The 1993 World Trade Center bombers rented a van and stored chemicals and fertilizers in that city.
Open jubilation at the mass death, Mr. Farmer said, might quickly be followed by rioting and more deaths. “If true, we would have had to mobilize the State Police and National Guard and locked the place down,” he said.
“We followed up on that report instantly because of its implications,” he added. “The word came back quickly from Jersey City, later from Paterson. False report. Never happened.”
Political campaigns are notorious for the damage they do to truth, but Mr. Trump’s presidential run has erased any lines that would segregate rumors, facts, mistakes and outright falsehoods. This month, he posted a graphic on Twitter that purported to show that 81 percent of white murder victims were killed by blacks; in fact, 82 percent of whites are murdered by whites.
Confronted by Bill O’Reilly, Mr. Trump essentially shrugged: “I retweeted somebody that was supposedly an expert, and it was also a radio show.” He has said, variously, that 200,000 or 250,000 Syrian refugees would be coming to the United States; the Obama administration’s actual goal for next year is 10,000, as FactCheck.org reported.