BOOK REVIEW / FICTION : A Maverick Cop Brimming With Troubles and Feeling : THE LAST COYOTE <i> by Michael Connelly</i> ; Little, Brown $22.95, 400 pages

The maverick cop is one of the staples of crime fiction, from Dirty Harry to all the ex-mavericks who couldn’t take the bureaucracy any more, or who finally broke one rule too many and had to leave, and so became maverick private investigators.

Michael Connelly’s Los Angeles Police Department homicide Detective Harry Bosch (real first name Hieronymous) is the most interesting (because the most thoughtfully perceived) of the mavericks to come along in years. His first appearance, in Connelly’s debut novel, “The Black Echo,” won an Edgar in 1993 as best first novel of the year. Harry’s fourth outing, in “The Last Coyote,” is the most ambitious, skillful and moving of the series.

The coyote of the title is one Harry sees, caught in his headlights before disappearing into the foggy night in the Hollywood hills. It is, as he knows, a perfect metaphor for Harry himself: wary, solitary, an imperiled breed in a hostile environment.

Harry hasn’t left the department yet, or been canned, but it’s obviously only a novel or two away. As the new book starts, Harry is on administrative leave (no gun, no badge, no car) for having--at least somewhat inadvertently--tossed his lieutenant through a glass partition. The lieutenant is a martinet-jerk who’s never worked the streets, but still.

Harry’s small house on Woodrow Wilson has been red-tagged since the quake and he has to sneak in and out to live in it at all. There’s no woman in his life, only too many cigarettes, a little too much liquor and way too much feeling. A woman he meets in Florida tells him, “You’re not like most cops I’ve known. You’ve got too much humanity left in you. How’d that happen?”

The novel explores and answers the question. Harry decides to use his leave to address his nagging guilt and explore an unsolved crime: the murder of his prostitute mother when he was not yet a teen-ager. She had wanted to get off the game, he knew, and she loved him deeply; but the system had taken him away from her, into McLaren Hall and then a series of foster homes. After a hitch in Vietnam, he’d joined the police department. Why as a cop hadn’t he dared look into her murder before?

Even a quick glance at the case file, dusty from its years in storage, left no doubt there had been a cover-up, and some of the interviews had at some point been torn out and presumably destroyed. The murder happened 35 years ago (Bosch is in his mid-40s), but even his first guarded inquiries stir things up and make clear that guilt, fear and danger still cling to the crime.

Connelly, who covered crime and the criminal courts for the Los Angeles Times for several years before he left to be a full-time novelist, writes about the city with an evocative accuracy that recalls no one so much as Raymond Chandler, though without Chandler’s sometimes hard-wrung figures of speech.

*

Harry takes his lumps along the way (more first-rate scenes); he’s slugged, kidnaped, shot. As in more traditional puzzle mysteries, but less obviously, the scenes and the action lead to a denouement. In fact, the author has provided Harry, and the reader, with not one but two last revelations--quite unexpected surprises which, however, flow convincingly from the whole context of the book.

The novel is thus not only a smashing police procedural (from his years on the beat Connelly knows the department and police routines very intimately), it is also in the end an intricate and clever mystery.

But at the heart of the book is Harry himself, in whom Connelly has created not a type but an individual. “Sometimes I think that I know strangers better than I know anybody else, even myself,” Harry tells a new woman in his life. “I learn so much about people in my job. Sometimes I think I don’t even have a life. I only have their life.”

The wise police psychologist, a Chicana and one of Connelly’s many fine creations, tells Harry, “The past is like a club and you can only hit yourself in the head with it so many times before there is serious and permanent damage. . . . Don’t do this.”

She reminds him he is a good man, and so he is. He is also a fully realized police officer, ringing as true in his milieu as, say, Maigret did in his or Gideon of the Yard in his.