COVER STORY by Gerry Boyle, Berkley Prime Crime Book (Penguin Putnam), New York, 2000, hardcover, 371 pages, $22.95.

Author Gerry Boyle is back with his sixth mystery centering on Mainer Jack McMorrow, a stubborn investigative reporter who lands in the middle of many a mystery or murder. This time, Jack is back in New York City, excited about doing some writing for The New York Times, which he left some years ago for the tranquility of Maine.

Now, instead of getting himself in trouble with Maine authorities, he meets an old friend and within 12 hours he is in the middle of a murder case. The murder is hardly a minor one — the mayor of the city is dead, stabbed to death in a hotel restroom, and Jack’s old friend, ex-cop Butch Casey, is accused of the crime. It’s a big, big story — a “cover story.”

Of course, Jack delves into the investigation, even as he is under suspicion as a partner in the crime. Jack and Butch had drinks together on Jack’s first night in town and, since the murder took place the next morning, police think Jack may have aided his buddy; if not, he might have some knowledge about the crime.

McMorrow has two motives and the author neatly develops them: On the one hand, he wants to help his old friend; on the other, here is a BIG story, maybe the biggest story in New York, and Jack’s reportorial adrenaline is working overtime.

Boyle also gives us a tantalizing taste of romance. Jack, who is in love with the beauteous Roxanne in Maine, meets up with his former New York lady, Christina. Except he doesn’t just meet her, he ends up staying with her in her loft apartment when the media keep pounding on his door.

Along with the mystery of whether Butch did the dirty deed or not, Boyle also gives us an unflattering look at how the big-city media work. When Jack is picked up by police and interrogated, then released with instructions not to leave town, the media go into a frenzy. Newspaper reporters, TV people, Hollywood filmmakers track him down. Jack tries to duck them all, but does agree to an interview with the Times, figuring he’d get an even-handed article from that. He doesn’t.

In previous novels, Boyle pits Jack against authorities as well as murky characters who commit all kinds of mayhem, some of it aimed at McMorrow. He remains true to that plot technique in this novel. Jack not only is dogged by two homicide detectives, Ramirez and Donatelli, but he is threatened by an unknown caller who probably had a hand in the murder. That puts not only Jack but Christina and Roxanne at risk.

Another element in the plot is the actions of the media. Print and TV reporters alike are exposed as slash-and-burn types who will do anything to get a story, and that’s true whether it is a sleazy tabloid or the once-staid “Gray Lady of New York” — the Times.

After Jack is trotted out as a suspect by police, the media’s feeding frenzy begins. Here’s a sample:

“One of the tabloid guys said he wanted to be more specific, that he was talking `high five figures.’ One woman said she was calling from Los Angeles, that she represented some very big people whose stories were potential properties. She’d just love to talk. Could I come to L.A.?”

In past novels, we have been given some fast-paced dialogue plus delightful descriptions of the Maine scene. Here we have terse, irreverent dialogue plus gritty descriptions of the New York scene. But he doesn’t forget his Maine roots. At one point, he is asked about where he lives. He replies, Prosperity.

“Prosperity is right alongside towns named Freedom and Liberty.” And then he notes that “where I live they tend to shoot deer, not people.” His buddy responds, “Well, that’s ’cause you got more deer than people. If we had deer in New York, we’d shoot ’em, too, especially if they were carrying money.”

Boyle gradually unfolds the possible reasons for the murder. It hinges on the earlier murder of Butch’s wife, and the killer got off through some machinations by then-prosecutor John Fiore. By the time Jack and Butch get together on Jack’s first night back in the city, Fiore has become mayor. Butch hints he has evidence that Fiore’s a crook and he wants Jack to investigate.

The next morning, Fiore is stabbed to death, Butch is arrested and Jack finds a package of clippings and notes at the hotel front desk.

Of course, Jack does investigate and finds a pattern of crimes solved and crime rates down, factors that enabled Fiore to get elected mayor. But Jack also finds that a number of the “perps” have mysteriously been released and many have simply disappeared.

Boyle continues his very effective first-person style as he reveals to us the introspective, sometimes wily 40ish guy. His description of New York and the New York scene is graphic. He provides us with a quick understanding of the social environment and atmosphere of the city. Characters, aside from Jack and Christina, are not pictured in depth — and, in fact, there is no need to develop other characters in any detail.

But it is the plot and the conflicts that carry this novel along. It’s another good read from the writer.

Gerry Boyle is a columnist for the Central Maine Morning Sentinel and lives in China with his wife and their three children.

Bill Roach is a free-lance writer with Maine roots who now lives in Florida.