Bradford G. Brown spent more than four years in prison for a murder he did not commit. Now he is suing the District of Columbia for $5 million under a law passed by the City Council specifically to allow him to be compensated for those years lost behind bars.

Brown's ordeal began in April 1975, when he was arrested and charged with the November 1974 murder of a man named Rodney Frazier during the course of a robbery attempt. It ended in July 1979, after D.C. police discovered that another man had shot Frazier.

"The question was, what does he do to get compensated for the mistake," his lawyer, James A. Bensfield, said yesterday. Brown couldn't sue the city because city officials are immune from suits unless they acted maliciously. Bensfield said that did not appear to be the case in the prosecution of Brown since an eyewitness who identified Brown as the murder suspect turned out to have been mistaken.

Brown, who has been unemployed for the most of the two years since his release, declined to discuss the suit, but told a reporter, "You can write that I need a job real bad. It's tough out here."

Bensfield said D.C. City Councilman David A. Clarke (D-Ward 1) agreed that something should be done for such persons as Brown who have been unjustly imprisoned. Some council members feared that it would be expensive to compensate such victims, Bensfield said, but research showed that very few people would be eligible under restrictions written into the legislation.

"It appears likely," Clarke wrote last year in a memo to other members of the council's Judiciary Committee, "that the fiscal impact of this bill over the next five years will be the cost of compensating Mr. Bradford Brown."

The City Council passed the bill in October and Mayor Marion Barry signed it a short time later.

The law, known as the Unjust Imprisonment Act, does not specify any maximum amount that Brown or anyone else can receive, but it does require that such damage cases be tried only by judges, not by juries, which would tend to reduce the possibility of an award the size Brown is seeking.

Bensfield said Brown, now 34, had been in and out of jail before he was convicted of the Frazier slaying, serving time twice for assault and robbery.

Since his release two years ago, Brown has not been arrested, Bensfield said, but he also has not been able to find a steady job. He worked for awhile as a janitor, then tried to make use ofsewing skills he learned at the Lorton Reformatory to become a tailor, but neither job lasted very long.

In recent months, Brown has been employed, when he can find work, as a day laborer, Bensfield said. Brown has custody of his 7-year-old daughter and lives in an apartment a floor below his mother's unit in a building at 1842 Providence St. NE.

After his release, Brown appeared in a nationally televised interview about his case, Bensfield said, and "some producer from Hollywood offered to buy the rights to his story for $1,000 or $5,000," but nothing came of the offer.

Bensfield said he is confident Brown will receive compensation since the law was passed specifically with him in mind. In his memo last year, Clarke said that the law would apply only to persons who actually spend time in prison, not just in pretrial detention, for crimes they did not commit and who could show through a judicial determination or presidential pardon that they were unjustly imprisoned.

The last pardon granted by a president on grounds of innocence was granted in 1965, Clarke said. The U.S. Attorney's office confirmed that there has been only one known D.C. case in recent years that meets the law's restrictions.

That was the case of Bradford G. Brown.