William Caunitz is a member of New York's finest and has been for 29 years. Fifty years old and with a policeman's rank of detective lieutenant, Caunitz follows a beat from 11:20 p.m. to 7:50 a.m. that sends him after pimps and prostitutes in Long Island City. But for a decade now, Caunitz has succumbed to an avocation he's unable to resist: writing fiction based on his experiences as a cop. Often up and out of bed by 11:30 a.m. after sleeping less than four hours , he writes every single day. If he doesn't, he says, he feels like he's ''going crazy.'' He adds, unnecessarily, ''I've been hooked.''
Caunitz got books into his head after recounting several episodes of his police work to Tony Godwin, one of publishing's most respected book editors, whom he met 10 years ago. Godwin liked what he heard and encouraged Caunitz to write it down. Caunitz complied and then sent off his first draft to Godwin, who returned it covered with deletions, corrections, and editorial suggestions. Even with all that was unusable in the first attempt, Godwin noted that the project had promise.
Another editor, Marion Wheeler, worked with Caunitz after Godwin's death, and she got him to literary agent Knox Burger, who also saw potential in the manuscript. The book finally made it to editor James O'Shea Wade, who worked on it with Caunitz for three more years. The payoff to all this: Caunitz's novel ''One Police Plaza'' has just been published by Crown to enthusiastic critical response.
The book is a gritty, thoroughly believable portrait of a police force in action. It's vulgar and bawdy and alive with the feeling that this is the way it is when men and women face crime, danger, corruption, and perpetual mounds of paper work day after day. Its procedural side is more successful than the portrayal of the police force's actual unmasking of a vicious plot to disrupt American life, but even this leads to a scene cataclysmic enough to raise a reader's adrenaline.
Was the long haul worth it? ''I knew it would come to pass,'' says Caunitz, a gray-haired, soft-spoken man with an unwavering gaze. ''When I first got the galleys, I thought to myself: 'Geez, it's a book!''
The wonder is not misplaced. Caunitz says he rewrote ''One Police Plaza'' over and over and over again - ''Seems like a hundred times'' is how he puts it. ''I have thousands and thousands of pages of early versions, cartons and cartons of them. Really, I guess I rewrote it at least 15 times from beginning to end. I was determined to do it.''
Godwin's initial assessment that Caunitz's hesitant prose did hold promise is what caught him. ''It was a challenge,'' he says. ''That's when I got hooked and wanted to write.''
Caunitz knew he had some apprenticing to do. ''I had to learn how, so I looked at what other people wrote. I've always read a lot, but you read differently when you're trying to learn. I read Donald Westlake and Lawrence Block. Martin Cruz Smith, who told me, 'Less is more. Use adjectives sparingly.' ''
''One Police Plaza'' basically followed the same story in the beginning that it does now, Caunitz reports. ''The plot did change somewhat,'' he says. ''When Knox first started sending it out, he'd get back form letters from publishers. Later, after more work on it, he got personal letters saying they liked it, but with some changes requested. I didn't make them all, but I did a few. Remember, I wanted to get published.''
But when it came to the job of writing, Caunitz finally reached his breakthrough, beginning to get up in the morning eager to read what he'd written the day before. ''Writing is always a struggle,'' he says. ''But now I know what I'm doing. Writing is a skill or an art form, or whatever it is, but if you stay with it you learn.''
One thing that Caunitz finds vital is being alone when he writes. He can't perform with others around. Although he has two daughters, he is no longer married, a victim of the common malady of policemen: the inability to hold a marriage together while working as a cop. ''It's a bad problem,'' he says.
''There's one thing that women demand,'' Caunitz says. ''It's time. They want to know, 'What're we going to do after Christmas?' or 'What'll we do next weekend?' A lot of policemen don't have the time to give. I didn't.''
On the other hand, a number of Caunitz's fellow police officers have found time to read ''One Police Plaza'' and have responded favorably, he says. ''And that's the thing,'' he says, gesturing at a book, ''to have the recognition, to have your name on the jacket. You can't think about the money much. Knox told me , 'Don't have delusions of sugarplums.' ''
Nevertheless, it's a rare author who isn't hopeful that something financially satisfying can be derived from what arises from the imagination. Caunitz is well into his second novel and has planned his third.
When we met him, Caunitz was about to read Joseph Wambaugh's new book, ''Lines and Shadows.'' Readers of police fiction will recall that Wambaugh was also a policeman. But no longer. His books and the movies based on them have proven eminently satisfying financially. Does Caunitz hope to emulate Wambaugh and write about crime rather than prevent it?
When asked, Caunitz nods his head wearily. ''A few days ago I was rolling over the rooftops with a guy who had been breaking in someplace, and I thought to myself, 'What . . . am I doing this for? I've been doing this for 29 years. I'm tired.' ''