Miguel Cruz, an 18-year veteran of the New York City Police Department, testified under oath that he visited his brother several times a week at his apartment on West 16th Street in Manhattan.

It turned out to be a pivotal moment in a classic New York court battle over a $151.47 a month, rent-controlled apartment. The landlord said Mr. Cruz’s brother, Victor, had lost his right to the apartment because he didn’t actually live there. The police officer said he did.

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