In 1941, a police recruit named John T. Downer began walking a beat in Brooklyn’s 84th Precinct, and was taken out to lunch by a patrolman.

“The meal was probably a buck and a half,” recalled Mr. Downer, who is now 100, but remembers the day clearly.

“The bill came and the sergeant told me, ‘Now kid, this is not a freebie — we pay by leaving a tip for the waitress,’ ” recalled Mr. Downer, who said he quickly learned that many restaurants offered the police meals free of charge, or “on the arm” in police parlance. He recalled a cashier at another restaurant on Eastern Parkway who took his $10 bill and casually handed him back two fives.

When he complained to the owner, he was told “I like policemen — you protect my store while you’re here,” recalled Mr. Downer, who retired as a deputy chief inspector in 1973 after a 32-year career with the New York Police Department.