Grouches and cynics who like to believe that old-fashioned honesty withered and died in the acid rain of modern life, read no further.

There comes from the township of Dobbs Ferry, N.Y. the cheering tale of an upright lawman who kept his word and his honor in the face of a $3 million temptation to wheedle and backtrack away from a promise. Our hero is police detective Robert Cunningham, 55. For the last eight years he's been a regular at Sal's Pizzeria in nearby Yonkers, N.Y., where Phyllis Penzo has waited on tables six nights a week for the last 24 years. Two weeks ago Cunningham was about to settle the tab on his usual meal of linguini and clam sauce when, on impulse, he offered Phyllis a deal instead of a tip. "Hey, Phyl, I've got a lottery ticket in my pocket," he said. "Why don't we split the card?" Penzo sat down and helped Cunningham choose the numbers for his $1 entry in the New York State Lotto Competition.

On April Fool's Day Cunningham called Penzo at 9 a.m. to tell her he had just won $6 million dollars and that she was entitled to half of it. "I was still asleep," she remembers. "I said, 'Don't bother me now.' " Cunningham convinced her that it was not a joke. She screamed, and woke her husband, Robert, a construction worker, to tell him they were rich. The two families will split the lottery payout of $285,715 a year over 21 years.

Cunningham, a 30-year police veteran with a salary of $30,000, insists that he never considered keeping all of the money for himself. "I've been a simple person all my life," he says. "If I say I'll do something, I do it. I hope money never changes me." Nor did his wife, Gina, 50, complain about him being overly generous. "I told her I had a partner and we were splitting down the middle," he says. "That was it. That is how our family operates."

The homespun millionaires have modest plans for spending the money. Cunningham wants to add on to the house that he and Gina, who have four grown children, share with her elderly parents. Penzo, who has two grown children, plans to buy a house so that she and Robert can move out of their rented apartment.

Surprisingly, both Cunningham and Penzo are anxious to get back to work. Cunningham has already assured his colleagues he is not quitting. "I love my work," he says. The argument that twice as much money might make him twice as happy doesn't convince Cunningham. "I play it straight down the line," he says. "I've always been that way."