The FBI says other law enforcement authorities have been alerted, including the U.S. Capitol Police the day before the Capitol violence over an online post about a "war".

FBI intelligence analysts gathered information about possible U.S. Capitol violence on Jan. 6. this week. But the FBI never distributed a formal intelligence bulletin, in part because of concerns that doing so might have run afoul of free speech protections, a current and two former senior FBI officials are familiar with the matter told NBC News.

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Although the FBI shared some threat information with law enforcement agencies, the lack of a detailed Joint Intelligence Bulletin collected by the FBI's Intelligence Division would have analyzed possible threats and shared them with local law enforcement agencies. It left the Capitol Police and other agencies without a complete image of what the FBI had learned.

"For every major event held in D.C., and even in sporting events like the World Series, they produce a Special Event Bulletin," a former FBI analyst addresses, adding that the paper is also known as a Joint Intelligence Bulletin. A second former FBI official also said this time did not happen because of fears that social media analysis by the content FBI analysts amounted to protected free speech.

The Washington Post reported Tuesday that a report circulated by the FBI field office in Norfolk, Virginia, the day before the riot notice that extremists were going to Washington to wage "war" and storm in capitol violence.

Domestic terrorism's disparate treatment goes beyond intelligence, the officials said. When there is a big event in Washington, major "subjects" of international terrorism are placed under 24/7 FBI surveillance "to ensure they don't try to do anything during the event," the former analyst said. "Nothing like that happens for domestic terrorism subjects."

When President Donald Trump's supporters came to town last month, there were rumors of unrest, and the FBI tracked everything from social media to the hotels where some of the rioters were staying. One indication of the preparations for possible Capitol violence came in the days leading up to Trump's rally last week, just before the attack happened, when the Washington Metropolitan Police arrested Enrique Tarrio, leader of the Proud Boys, after leaving the airport on his way to his hotel.

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At a previous Proud Boys march in Washington, he was charged with his role in smashing a Black Lives Matter flag, and prosecutors later added charges of possessing two expanded munitions magazines that are illegal in the region. A local judge ordered him to leave town as part of his release and to stay away from last Wednesday's rally.

He said that every piece of information the FBI obtained from social media and human sources about the possible violence was shared with members of a D.C. Members are Area law enforcement organization known as the Joint Terrorism Task Force, which involves the Metropolitan Police Department Washington U.S. Police Capitol.

The "written product" was not a formal intelligence bulletin, said the present and former officials familiar with the matter.

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