By John Sandford

Putnam's. 318 pp. $18.95

In what reads like an effort to make cops in pop fiction more macho than some of the quieter, fallible ones introduced in recent years, John Sandford has invented a new sub-genre: the police procedural-bodice ripper. His Minneapolis undercover cop Lucas Davenport, star of last year's best-selling "Rules of Prey" as well as the new "Shadow Prey," unapologetically bangs around town in a Porsche that must be worth close to the annual income of the average Minnesota wage earner. With his local TV news-producer common-law wife, Jennifer, busy at work and home with their infant daughter, he seduces visiting New York City police detective Lily Rothenburg and fills her with fire, electricity and six or eight other elements that her academic jogger nice-guy husband, David, can't provide. Before Lucas gets to her, "she'd always worn soft pinkish lipstick, and just a touch." After Lucas, "her lipstick was hard and heart-red, the color of street violence and rough sex." Estee Lauder, check out the spinoff rights.

When Lucas wants information to solve a crime, he gets it: An Indian kid is set up in a dope bust so his mother will rat on friends in return for the boy's receiving juvenile status; an old Indian woman is punched between the shoulder blades when she runs from Lucas, who threatens to drown her in her bathtub if she doesn't spill the beans about her lover. An FBI wimp jokes, "Except for Davenport, we don't have the death penalty in Minnesota." The go-for-it '80s are over? Word hasn't reached Minneapolis.

"Shadow Prey" is a slick piece of work and would be hard to put down if it weren't for its weirdly conflicting values. Sandford starts off with a heartbreaking scene. In 1968 a young Indian girl in Phoenix gets drunk and is raped in an alley by a rotten cop. It's Larry Clay, the cop, that Sandford is interested in, and we follow his demagogic career up through the police ranks, into Congress, and eventually to the directorship of the FBI. Two Indian activists also follow Clay's career, which in its early years is built largely on Indian-bashing. Knowing of Clay's hidden sexual preference for young girls, they plan to lure him to Minneapolis and kill him. Part of the snare for the swaggering, gun-slinging director is a series of outrageous ritual murders of other whites who have hurt or exploited Indians: a slum landlord, a racist parole officer, a cynical Manhattan welfare pol, a federal judge, the attorney general of South Dakota.

The Indians are convincingly portrayed here as such pathetic victims -- neglected, duped, hounded, abused -- and the white murder victims as such ghastly human beings that for the first third of the novel we can't wait for the next evil character to get his throat slit with an obsidian knife. A number of times I had to stop and think about how the conquered peoples of Eastern Europe are recovering their freedom these days and the conquered peoples of North America are not and will not.

There's an especially affecting brief scene where Sam Crow, one of the killers, explains why he's become a murderer and why he'll be a martyr. "It's almost necessary," he says, "that we ... die. The people need this story. You know, when we were kids, I knew people who knew Crazy Horse. Who's alive now to talk to the kids? The only legends they have are dope dealers."

Although this speech comes two-thirds of the way into the novel, it is uncharacteristic because it is a good hundred pages past the point where Sandford seems to have lost interest in the Indians -- one-dimensional psychos, addicts, losers -- and turned to his real love: Mr. Macho Man, Lucas Davenport, cop, expert marksman, successful computer-game inventor (this pays for the Porsche), and, as Lily Rothenburg ruefully describes him, a "relationship junkie" who "always needs something new."

Does Lucas just want sex? "No. The woman. The back-and-forth. Hanging around. The sex. Everything."

We get an awful lot of the back-and-forth in "Shadow Prey" -- and the sex too: "absolutely terrific; the best of their lives" -- and while some of the back-and-forth is stylish and occasionally witty, it's hard to stay interested in Lucas's personal ups and downs when always just in the background is the tragedy of an entire people. You want to say, okay, go to it, Lucas, if that's the life you want to lead, but how about a closer look at the people whose problems and struggles with them are so much more profound, or even just more interesting?

There's an inconsistency and apparent cynicism about "Shadow Prey" that might have to do with commerce. Some scenes are written with a cinematic flavor suggesting that an eventual move into the Cine-10 out at the mall is not unanticipated. We get high-speed chases, a gunfight in a brothel, a gunfight on the street around a hostage, a gunfight in a darkened hotel room, a gunfight in Davenport's house with Jennifer and the baby curled up in a gun cabinet. You can almost hear the Dolby sound of it pounding in your skull as you read.

For a terrific thriller about American Indians and the fascinating, real -- usually Indian -- cops who live and work among them, skip "Shadow Prey" and read the latest Tony Hillerman.

The reviewer is the author of three private-eye novels under the pseudonym Richard Stevenson.