Attorney General Michael B. Mukasey collapsed during a speech on Thursday night, being taken to the hospital after he failed to regain consciousness. Mr. Mukasey, a 67-year-old, took over as attorney general one year ago, after the resignation of Alberto R. Gonzales. He was giving a speech on national security to members of the Federalist Society, a conservative legal affairs group, when he lost consciousness at about 10:20 p.m. The spokesman, Peter A. Carr, told the media that the attorney general is conscious, conversant and alert and that he would be kept overnight at George Washington University Hospital for observation: “His vital statistics are strong and he is in good spirits. He is receiving excellent care and appreciates all of the good wishes and prayers he has received.”

Michael Mukasey, a former judge and prosecutor in Manhattan, has reported no medical problems recently so, therefore, there was no immediate indication of the cause of his collapse. Several members of the Supreme Court had been expected to be at Mr. Mukasey’s speech before the Federalist Society. The attorney general planned to talk about the continued threat of Al Qaeda and the changes the government has been through since the September 11, 2001, attacks in order to guard against other attacks. As a judge after the September 11 attacks, he ordered the detention of young Muslim men as so-called material witnesses in terrorism cases. Of course, immigration lawyers criticized him for this decision and the Justice Department praised him.

The latest information shows that Mukasey has left George Washington Hospital early Friday afternoon, apparently headed for his office. After a night of observation and underwent routine tests, he earned “completely normal” results on a stress test this morning. Spokeswoman Gina Talamona said that Mukasey has received a “clean bill of health.”