The group plans to ask that Officer Joshua DeWees, who is facing three federal lawsuits alleging misconduct, be suspended immediately pending an independent investigation.

For a town meeting scheduled after the march, the NAACP has invited local officials to address "apparent systemic incidents of police misconduct" that residents have reported.

The first suit involving DeWees was filed in January by a girl who was 14 when she was arrested in January 2007 and charged with disorderly conduct and resisting arrest. She alleges that DeWees struck her on an arm with his baton. The charges against her were dismissed, according to court documents.

Two more lawsuits were filed last week.

Gerald Turner, 52, of Bear, Del., was coming out of a Sunday church service in Chester in December 2007 when, he said, he witnessed an auto accident and offered to give a statement to DeWees. The suit alleges DeWees wrongfully arrested Turner on a disorderly-conduct charge after Turner asked for his badge number and DeWees directed expletives at the church pastor. A hearing on the charge was never scheduled, according to court documents.

Julia Quagliarello, 18, a Widener University student from Ridley Park, was driving to class in January when, according to her lawsuit, DeWees pulled her over and ordered her from the car at gunpoint. She was charged with trying to flee a police officer and disorderly conduct. The charges were withdrawn, according to court documents.

Harry J. Oxman, an attorney for the three plaintiffs, said that "the complaints speak for themselves" and declined to elaborate.

A message for DeWees was not returned. Calls and e-mails to his lawyer, Harry G. Mahoney, also were not returned.

Mayor Wendell Butler did not return calls. Calls to Police Chief Floyd Lewis were referred to Emily Harris, communications director. Harris said that the city does not comment on ongoing litigation, but that it would release a statement at the 3 p.m. rally. She added that Butler and Lewis would attend the town-hall meeting.

Asked about DeWees' status, Harris said that "he is still on duty."

Darrell Jones, president of the NAACP in Chester, said there had been "several" other complaints from residents about police. He would not go into specifics, but said they went beyond DeWees, adding that the three in court were the most serious allegations.

Asked why the NAACP had gotten involved, Jones said, "We're trying to get to the bottom of it and see what's going on. . . . If the allegations prove to be true, they are shocking."