FBI boss facing questioning on September 11

The investigation by the US Congress into why the FBI did not anticipate the September 11 attacks is entering a new public phase, with Director Robert Mueller facing tough questioning from senators.

‘‘The thrust of our questions is going to be, did people connect the dots? Did people put two and two together? And if they did, why did this ever happen?’’ said Senate Judiciary Committee Chairman Patrick Leahy said.

Coleen Rowley, a lawyer in the FBI’s Minneapolis office, sent Mueller a scathing letter on May 21 saying he and other senior FBI officials had misrepresented what they knew ahead of the attacks.

Rowley said the officials were trying to ‘‘circle the wagons’’.

She also claimed FBI headquarters shelved her requests in the weeks before September 11 to aggressively investigate Zacarias Moussaoui, who was being held in Minnesota and is now the only person charged in connection with the attacks.

Rowley was to testify before the Senate committee later today.

‘‘I want her to tell me as best she can what is wrong at headquarters that so many things like the Moussaoui investigation get stonewalled there?’’ said Senator Charles Grassley, an Iowa Republican.

The House and Senate intelligence committees, meanwhile, met yesterday for a second day of closed-door hearings without calling any witnesses, while several inquiry staff members went to FBI headquarters to question Rowley.

Leahy said he will press forwards with the inquiry because of the committee’s constitutional obligation to ensure the FBI is adequately protecting Americans.

‘‘We have the ultimate responsibility to report on whether there were mistakes made,’’ he said.