“We have a goal, and the goal is to establish the facts because only when you establish the truth can you then find the basis for a political solution and a future solution,” Mr. Bassiouni said on a day he met both King Hamad bin Isa al-Khalifa and the head of the largest legal opposition group.

But in a society where no one even agrees on the share of the Shiite majority, or who really wields power, this is the question facing Bahrain and so many other countries: Is it possible to reveal, let alone agree on, the truth?

Nature of the Repression

The commission bears the mark of one of the world’s leading experts in international human rights. Mr. Bassiouni essentially drafted Royal Order No. 28, which outlined the commission’s task, and chose the four other members, all recognized internationally in their fields.

In 14-hour days, often stretching far longer, the commission carried out 2,343 interviews, took 4,483 statements, held 48 meetings and carried out 35 investigations, one of them stumbling on a jail where an adolescent had been burned by a cigarette butt only minutes before. (By virtue of the visit, the youth was released, and police officers suspended.)

The report is expected to detail the scope of the crackdown, beginning in March, in which Mr. Bassiouni said “it was fairly standard procedure to mistreat people.” He said investigators had compiled more than 300 cases of abuse, 64 qualifying as torture. About 3,000 people were fired from their jobs, and more than 1,000 students dismissed from college. (About 500 employees returned to work, along with most students.) The commission documented 30 instances in which the government destroyed or damaged Shiite religious sites, inflaming the sectarian divide.

“It’s not that they went and destroyed St. Peter,” said Mr. Bassiouni, who has an academic’s zest for intellectual give and take that is not always suited to the reserve of diplomacy. But, he added, “if these places meant something to them, and they felt that they were their religious places, the government should have respected that.”