Prolific true-crime and mystery writer Jeffers (A Grand Night for Murder, 1995, etc.) details a neglected chapter in American criminal history--but a chapter may be all the story merits. Gerald Chapman was a product of underprivileged Irish stock in turn-of-the-century New York who got his start in crime before Prohibition industrialized it. Under the tutelage of an older, more sophisticated crook whom he met during one of his many imprisonments, Chapman became a dapper, poetry-writing man about town, ""the Count of Gramercy Park,"" while pursuing a career in burglary, swindling, and armed robbery that ended in his execution for murdering a policeman. Jeffers seems to know the era and generally has a nice touch with period color, especially in his description of Chapman's ultimate trial and the tabloid coverage of his final months; it is startling to read of the glamour that the public attached to criminals in the relatively innocent '20s. But Jeffers has neither the subject nor the sources to make this a fully satisfying true-crime story. The description of Chapman as ""America's first Public Enemy No. 1"" is misleading; he was not the first FBI ""most wanted"" but simply the first criminal to be so called in print. Although he made a couple of interesting escapes, he was not clever enough to avoid getting captured with head-spinning frequency. Faced with significant gaps in the documentary record, and perhaps needing to liven up an otherwise uninspiring story, Jeffers pads the book with invented scenes and hackneyed dialogue ("" 'Finding one check passer in this town is looking for the needle in the proverbial haystack,' O'Brien said. 'And believe me, New York is one hell of a pile of straw.' "") Mildly entertaining, but not likely to add Chapman to the ambiguous pantheon of American crime.