At the recent Mystery Writers of America banquet, an event held each spring to honor to Edgar Awards winners, Margaret Truman stepped up to the dais from her table and spoke very briefly. With a first mystery of her own about to come out, she was honored, she said, to be asked to address a gathering of so many writers whose work had given her so much pleasure. Then she sat back down.

For a moment, the expectant diners were confused, dissatisfied. Anticipating a speech, they got a polite greeting. But quickly the business of the evening -- award-giving -- began, and Margaret Truman was forgotten, left to sip her coffee like any other tyro in the ballroom of the Baltimore that night.

The mystery genre has absorbed many novices. In the '40 and '50s it was show-biz celebrities, like Gypsy Rose Lee, George Sanders and Helen Traubel, who wandered in from other worlds. But these "star" mysteries were generally ghost-written by professionals and, though often amusing, attained only novelty status. Aside from the efforts of New York's John Lindsay and a few others, it was not until the post-Watergate era that we had politicos (Ehrlichman, Agnew, the Steins, et al.) trying their hands -- not until then did we have such a plethora of (former) high government officials with the financial incentive to dream up plots, the notoriety needed to sell the projects, and the leisure (often enforced) to write them.

Margaret Truman, in her desire to pay homage to a form of literature towards which she feels such affection, has produced a novel more in the mode of Traubel's "The Metropolitan Opera Murder" than any of the published fictions of the Nixon gang. It's set at the White House because it's catchy and because she and the book must have been easy to pre-sell as a package. Yet "Murder in the White House" is not "cheap" or exploitative in any way that could offend, and it's really not so bad for a story that must have been a concept before it was full-blown idea.

White House watchers will no doubt be examining Truman's text for errors of fact or protocol. However, since a secretary of state has never had his throat sliced in the family residence before, it is somewhat difficult to gauge the authentically of what follows. Naturally, there is the problem of the overlapping jurisdictions of the FBI, the Secret Service and the metropolitan police, and, naturally, the president appoints a special investigator. This last-named is the character Truman chooses for her male lead; he is Ron Fairbanks, special counsel to President Robert Lang Webster and occassional companion of the president's attractive daughter, Lynne.

After Secretary of State Lansard Blaine, an academic "theoretician . . . given the opportunity to put his theories into practice" and a strong contender for a Nobel Peace Prize, is found "drenched with blood" in the Lincoln Sitting Room, things take on a casebook tone. Fairbanks, who is not at all sure if he's being set up to fail, tries his lawyerly best to act the part of "chief White House gumshoe," and keeps reminding anyone who's interested that he's so nonpartisan he never even voted for President Webster in the first place.

The transitions read like this: "Dominique's, Thursday, June 14, 8:00 P.M." Thus, Truman follows Ron on his investigative rounds, as he interrogates the myriad mistresses of the dead Cabinet member, for it is revealed quite soon after his demise that Blaine was an amiable satyr. Women, it seems, flocked to his Watergate apartment, where he seduced them with "champagne and caviar and pate." Not that he really had to woo them in earnest: Lansard Blaine merely had to express interest and women complied. "'No . . . quickies. He was a wonderful lover. I've never known anyone like him,'" says one ex-girlfriend, who, like the others, doesn't appear to have been perturbed by his amorous pluralism.

Truman, however, avoids making cherchez la femme the only route to a solution by throwing in other familiar sorts of motivation as well: multinational bucks and bribes, blackmail, etc. In short, the type of puzzle which could just as easily have been set at Buckingham Place or the Kremlin:

Probably few readers remember that FDR provided the plot for a group of mystery writers, including S.S. Van Dine, in 1935; the result was "The President's Mystery Story," first published in magazine serial and later in book form. Fewer still might remember that Helen Traubel novel memtioned above. But Margaret Truman, a first daughter coming from of a family of mystery readers and who had Traubel for a singing teacher, surely does. "Murder in the White House" indicates that Margaret Truman has been a loyal fan and an apt pupil. It is possible, at moments in the book, to sense the author's brow furrowing as she attempts to make a point or work something through. It is also easy to speculate that the scenario might be far different if a murder were actually committed within the sacred precincts. Nonetheless, Truman has upheld executive honor. w