(Reuters) – The FBI and key law enforcement agencies did not act on a number of tips that indicated a potential violent incident might occur at the U.S. Capitol on Jan. 6, the Washington Post reported Sunday.

In the weeks that followed the riot that erupted as legislators met to verify the presidential election results, officials were able to access information from several sources. According to The Post’s internal records, a tip received by the FBI on Dec. 20, the FBI learned that Trump supporters had been discussing how they could sneak guns into Washington in order to “overrun” the police and detain members of Congress.

This tip contained details that showed those who planned violence thought they were given orders by the president. They used code words like “pickaxe” and “pickaxe” as descriptions of guns and listed the times and locations at four places across the country where caravans could meet on the day prior to the joint session. The Post stated that a poster on one of the sites specifically named Senator Mitt Romney (a Republican from Utah) as a target.

Romney was one of seven Senate Republicans to vote for Trump’s conviction last February on one incitement to an insurrection charge. The House of Representatives levelled the same charge during the second impeachment of Trump.

A tip was evaluated by an FBI agent who noted that the FBI’s criminal division received “significant” alerts regarding threats to Congress and government officials. According to the Post, although the FBI provided the information to Washington law enforcement agencies, it did not follow up on the matter.

The internal report said that the Assessment identified individuals or groups did not merit further FBI investigations at this point. According to the Post.

It was one of many details in the report that included thousands of pages and interviews with more then 230 people. There were also hundreds of video, photos, and audio recordings.

An investigation by a special congressional committee is underway into the violent events of that day. This erupted after Trump staged a protest near the White House in his rage against the outcome of the election.

One person was killed by police while the other three died from natural causes. One of the officers who died was one of more than 100 injured police officers. Four other officers took their lives since then.

More than 600 individuals were charged for their participation in violence.