For three days in October, 1968, Roszel Thomsen was the best-known trial judge in the world. He presided over the trial of "the Catonsville Nine," anti-Vietnam War activists who had attracted international attention when they burned draft records in Catonsville. Judge Thomsen earned the respect of many in the peace movement by his fair and sympathetic management of the trial.

That moment was but the mid-point in a near half-century career of respected public service. It began with his appointment to the Baltimore City school board in 1944 and ended only shortly before his death Wednesday at the age of 91.

In 1952 as school board president, he led the city to end school segregation; later as a judge, he enforced elsewhere in Maryland the Supreme Court's 1954 ruling that school segregation was unconstitutional. He also was involved in high-visibility cases in which he ordered reforms in the procedures of the city police department and the state prison system.

He was a true conservative. At one point in the Catonsville Nine trial, he said something to one of the defendants that perhaps epitomizes his legal and personal philosophy: "I can understand how you feel. I think the only difference between us is that I believe the institutions can do what you believe they cannot do."