Steven Reed, a spokesman for the Bronx district attorney, Robert T. Johnson, said that the new policy of requiring interviews of officers “was discussed with the offices of the other district attorneys and the N.Y.P.D.,” but he would not comment further because of continuing litigation.

The new policy in the Bronx led to an Internal Affairs Bureau inquiry into the allegation of improper arrests, according to a letter sent by Police Commissioner Raymond W. Kelly to Mr. Johnson on Sept. 6. Mr. Kelly said that no misconduct had been uncovered, and that it appeared that Ms. Rucker’s “estimation of the issue was in error and that she overstated her perception of discrepancies regarding criminal trespass arrests in the Bronx.”

Mr. Kelly also suggested that Ms. Rucker was unable to provide specifics of the cases referred to in her letter, and that she could cite only one example in which she alleged an arrest was dismissed because of a police error. Nonetheless, he added that the legal issues surrounding trespassing arrests would be addressed at training sessions at the precinct and borough levels.

Mr. Johnson has adopted some independent positions before. In 2006, he became the first prosecutor to use the state’s 2001 antiterrorism statute, doing so against a street gang member. He also issued a statement in 1995 saying he did not intend to pursue execution in first-degree murder cases.

The letter from Ms. Rucker, who is the chief of arraignments for the Bronx district attorney, was filed in federal court this week in a lawsuit challenging trespass arrests in New York. The lawsuit was filed by Legal Aid and the N.A.A.C.P. Legal Defense Fund.

Prosecutors in the Bronx have been “experiencing a great deal of problems with trespassing” arrests, Ms. Rucker wrote in the July 18 letter. She wrote that she had received numerous complaints from defense lawyers who claimed that many of the people arrested were not trespassers. Deciding to investigate further, she found that “in many (but not all) of the cases the defendants arrested were either legitimate tenants or invited guests,” she wrote.

In some cases, Ms. Rucker claimed, the police arrested people even when there was persuasive evidence that they were not trespassing, citing “several instances where defendants who were guests, had the person whom they were visiting verify this fact to the arresting officer, yet the defendant was arrested anyway.” In those cases, the deposition from the arresting officer “indicated the defendant did not know the name of any tenant or the apartment number.”