The Brockman raid tests that principle of accountability against a wider field, because unlike the Spruill raid, the search of Mr. Brockman's home involved federal law enforcement as well as the police.

Mr. Kelly's spokesman, who provided a detailed account of the police involvement in the Brockman raid, said the department had started an internal affairs investigation into what went wrong.

The federal agents from the Justice Department said that the mistake was entirely the product of police information, although the police say it was the federal agents who came up with Mr. Brockman's apartment number at the last minute.

A spokesman for prosecutors in the office of United States Attorney James B. Comey said they were not allowed to discuss what, if anything, they knew about major discrepancies in the evidence when they asked a federal magistrate for permission to knock down the door to Mr. Brockman's home.

For his part, Mr. Brockman said that while he is still rattled by the episode, he was not physically hurt during the foray, just frightened for himself and for his cats. He said the authorities should have been better prepared.

''The police -- they're all right with me,'' Mr. Brockman said. ''I suffer from seizure. A lot of times I have fell out on the street, and they picked me up. You have people who say, 'The police are dirty, this and that.' I can't find any fault with them that I know of. They got a job to do. But I don't know why they came and broke into my house. I don't see any right in that. If they have me under surveillance, they would watch me, and see who's coming in and out. Not to come in like storm troopers.''

The events leading to the search of Mr. Brockman's apartment began with a ''rash of shootings'' in the early spring, according to Inspector John Cutter of the police Intelligence Division. In response, detectives sent out an informer who they believed had proven her reliability in other cases when she bought a gun and crack cocaine under police supervision, officials said. On May 5, undercover detectives shadowed the informer as she headed into the Edenwald complex, but they were not able to track which building she entered, Inspector Cutter said.