NEW YORK (AP) - The New York City Police Department must reinstate a black officer who was fired for publicly criticizing the department after the fatal shooting of an unarmed African immigrant, a federal judge ruled.

U.S. District Judge Alvin Hellerstein also ordered the department Wednesday to pay Yvette Walton, 39, $55,000 in back wages and remove any documents from her employment record related to her ``wrongful dismissal.''

Hellerstein concluded in November that Walton's First Amendment rights had been violated and that she would not have been fired if she had not criticized the department after the Feb. 4, 1999, shooting of Amadou Diallo. Diallo died after being shot at 41 times by police officers who said they mistakenly thought he had a gun.

Walton had worn disguises or had her voice electronically altered as she criticized the department at a news conference, on a national television program and at a City Council meeting in early 1999. She was fired soon after.

Walton had been the only black woman assigned to street patrols when she joined the newly created Street Crime Unit in 1993. She transferred out in 1995 after concluding that the unit targeted minorities in illegal searches and seizures.

The Police Department had no comment on the judge's decision and may appeal the case, police spokesman Thomas Antenen said. The department has said it fired Walton because of insubordination and violating departmental orders regulating sick leave.

Walton's lawyer, Christopher Dunn, told the Daily News his client looks forward to returning to the job ``she loves.''

Four officers assigned to the Street Crime Unit were tried last year and acquitted of all charges in the shooting of Diallo.