Tightrope by Teri White (Mysterious: $15.95; 240 pp.)

Roughly 300,000 Vietnamese refugees now live in California, and they are starting--slowly and quietly--to make their way into our novels. Last year’s “There’s Nothing to Be Afraid Of,” by Marcia Muller, involved Vietnamese characters in San Francisco, and now Teri White’s “Tightrope” is set partially amid the Vietnamese of Los Angeles.

This is a straightforward cops-and-robbers tale, in which two Los Angeles Police detectives are pitted against a trio of American war veterans--two of whom fought in, one of whom photographed--the war in Vietnam. These crooks are after a cache of diamonds brought to this country after the fall of Saigon in 1975, and the police are after whoever is leaving a trail of bodies in their city. It is Christmas time.

The cops are Blue Maguire and partner Spaceman Kowalski. Maguire comes from a wealthy family that has left him money: Police work for him is a pastime, not a paycheck. He drives a Porsche. Kowalski is a veteran cop and a “nicotine junkie.” Together they are a slightly uneasy pair, with Kowalski wondering secretly if Maguire belongs in department public relations (from which he has recently come), and Maguire suffering from a nonspecific malaise that causes chronic dreariness, and too much drinking. “It was a sad state of affairs,” White tells us, “when a man’s cat had a better sex life than he did.” Crockett and Tubbs they’re not.

The bad guys are led by Lars Morgan, a.k.a. Wolf, who kills without regret in his search for the diamonds that he himself helped smuggle out of Vietnam. His right-hand man is gigolo Toby Reardon, a picturesque hunk who is alternatingly brave and afraid. Working with them--against his own better judgment--is war photographer Devlin Conway. Like Reardon, Conway is drawn to danger and violence by Wolf’s odd power, just as he had been in Vietnam, “ever since that first day, in fact, when something he couldn’t explain then or now drove him to jump into that damned muddy hole to talk to the grey-eyed young soldier.”

“Tightrope” is less a mystery than a story of suspense. We know from the beginning what has happened--and by inference, what is about to--but we’re not sure how Maguire and Kowalski, both beset by their own personal problems, are going to catch the killer/thieves. The novel’s short chapters jump from one set of characters to the next, giving us a clear, on-stage accounting of the action. By the time the book is finished, we know as much about Wolf and his bad guys as we do about the police heroes of the story. White presents her crooks as lovingly as she does her cops.

“Tightrope” is a well-paced, economically written and fairly effective thriller. This is White’s third novel (her first, “Triangle,” won the Edgar Allen Poe Award).

But this novel suffers from a lack of atmosphere. For most of the book, we seem to be floating in time and space: Los Angeles recedes to the point of near invisibility. We have only to recall Chandler’s Santa Monica, John Gregory Dunne’s downtown Los Angeles (of “True Confessions”) to realize we’re missing a genuinely felt sense of the city in which this entire story takes place. This can be said of the Vietnamese refugees in “Tightrope” too. They are sketched in rather than truly observed.