Note: Correction appended.

Mayor Bloomberg’s insistence that New York City routinely inspect out-of-state gun stores recently led to a tense moment in a small Pennsylvania town.

The owner of a gun shop in Mount Penn, Pa., barred the city’s emissary from entering the store last month despite consenting to the visit in an earlier court settlement. At one point, the store owner, Jay Fisher of Gallery Distributing, shouted: “This is my store, and I tell you what is going to happen,” according to a report of the incident filed in federal court in Brooklyn.

The report, which says Mr. Fisher was armed at the time and behaving “in an erratic and threatening manner,” is the first public document to provide details about one of the more unusual and secretive law enforcement initiatives to emerge from the Bloomberg administration.

The report is signed by a prominent corporate attorney in Manhattan, Andrew Weissmann of the firm Jenner & Block, whom the city has enlisted to visit some two dozen gun shops from Pennsylvania to South Carolina. Mr. Weissmann’s mandate is to train and monitor the stores’ employees to ensure they take precautions against selling guns to felons and others who are disqualified from purchasing firearms.

Each of the gun stores on Mr. Weissmann’s itinerary had been sued by the city in 2006. The suits, which Mayor Bloomberg announced at a press conference, allege that the gun stores were public nuisances on the grounds that many of the firearms they sold were subsequently being recovered from crime scenes in New York. In order to settle the suits, the gun stores have nearly all agreed to open their doors to Mr. Weissmann.

Except for the most recent report about Gallery Distributing, all of Mr. Weissmann’s reports about his gun store visits have been sealed in U.S. District Court in Brooklyn at Mr. Weissmann’s request. No reason for the secrecy has been put on the court record.

With the reports sealed, it’s difficult to assess what effect the lawsuits and the settlements have had on the gun stores and their sales practices.

“I don’t think it’s worth anyone’s time,” a lawyer who represented several of the gun shops who were sued, John Renzulli, said of the effort to monitor the stores. “I think if the city could bow out gracefully it would.”

The court record doesn’t even mention whether it is Mr. Weissmann, or someone on his behalf, who is visiting the gun stores.

The court names Mr. Weissmann — not his law firm — as the “special master” chosen by the city to monitor the gun stores. It doesn’t contain a provision allowing Mr. Weissmann to delegate the authority to another.

Yet in a footnote in his letter regarding the visit to Gallery Distributing, Mr. Weissmann raises the possibility that he has bestowed the title of “special master” on two law firm associates as well as on a former federal agent he has hired as a consultant.

The footnote leaves it unclear who visited Gallery Distributing. Mr. Weissmann declined to comment yesterday.

The New York Sun reported in April that while Mr. Weissmann was devoting his time pro bono, two associates were billing the city $250 an hour to assist him.

Mr. Fisher of Gallery Distributing did not return a call for comment.