Researchers looking into the possible effects of affirmative action programs on law schools and the legal profession should have access to state bar exam scores and other records if individuals' privacy can be ensured, the state Supreme Court ruled Thursday.

The unanimous decision was a boost for UCLA law professor Richard Sander, who has been battling the state bar for five years to obtain the data. Sander wants the information to test his controversial theory that racial preferences in law school admissions might hurt minority students by putting them in overly competitive environments.

"It's a tremendous victory for advocates of public access and transparency," Sander said of the court's action. He is seeking bar exam scores, law school grades and ethnicities for more than 200,000 people who applied to take the state bar exam back to 1972.

He was joined in his case by the California First Amendment Coalition and others who want more scrutiny of government agencies — even if they don't agree with Sander's theories on affirmative action. Another co-plaintiff was Joe Hicks, the conservative civil rights activist in Los Angeles who opposes affirmative action and is a former member of the state bar's governing board.

But the case is not over. The Supreme Court returned it to the original Superior Court in San Francisco to decide if and how the material can be released without identifying individuals and without harming other public interests too much.

Sander said he long has been willing to accept the data with all names removed and with clustering of anonymous information over ranges of years as a further way to ensure confidentiality. He also has offered to pay for the cost of such privacy measures. The bar organization has resisted, saying it had to honor promises of confidentiality to law students.

Chief Justice Tani G. Cantil-Sakauye, who wrote the Supreme Court decision, agreed in principle with Sander.

"The public does have a legitimate interest in the activities of the state bar in administering the bar exam and the admissions process," she wrote. "In particular, it seems beyond dispute that the public has a legitimate interest in whether different groups of applicants, based on race, sex or ethnicity perform differently on the bar examination and whether any disparities in performance are the result of the admissions process or of other factors."

In a statement, Luis J. Rodriguez, the state bar president, said: "The Supreme Court has identified the issues. Therefore, the state bar will go back to the trial court to resolve the issues as identified in the opinion."

The Los Angeles Times and other news organizations had signed briefs of support for the release of the data.

The research will go beyond racial issues into helping students learn more about "how attending a particular law school affects their chances of becoming a lawyer," Sander said.

Affirmative action is banned at California's public law schools and colleges. Sander's research would include California bar exam candidates from private law schools and from public institutions in other states where affirmative action is allowed.

larry.gordon@latimes.com