The president's favorite mystery writer is Jewish and black and loves unusual stories. Just the other clay he saw a fountain... ELIZABETH APPLEBAUM ASSISTANT EDITOR ver since Bill Clinton announced his campaign for the presidency, the American public has been having a love affair with a certain devil. It was a passing comment that started it all: Mr. Clinton mentioned that one of his most pleasurable pastimes was reading murder mysteries by Walter Mosley. In no time, Mr. Mosley's The Devil in a Blue Dress began selling out at book- stores across the country, as did his sec- ond novel, A Red Death. His White Butterfly, due this month from Pocket Books, is expected to do equally well. Mr. Mosley does not fit the typical image of a detective-story writer. He's soft-spoken and thoughtful, not a hardened wisecracker who likes his whiskey strong and his women saucy. He speaks about the "music" in his books and says he loves his characters. He has been known to change major aspects of his plots at the last minute (like when the book is set to go to print.) He's black. And he's Jewish. Walter Mosley was born 51 years ago in Los Angeles, the only child of a black father, Leroy, and a Jewish mother, Ella. It was a home in which Walter felt tremendous love and that nurtured his identity as both a black and a Jew. "My parents were always happy with who they were and who I was," he says. Walter's father, Leroy, was a native of New Iberia, La., a place best-known as the Tabasco capital of the world. Leroy's mother died when he was 7, which Walter calls "the greatest tragedy of his life." His father, about the only one in town who knew how to read, disappeared when Leroy was 8. He went out one day and never returned. The early loss of his parents forever' \ shaped Leroy Mosley's character. Much of Leroy remained childlike — "not in a spoiled way" but reflected in the wonder and creativity with which he regarded the world and lived his life, his son says. After serving in North Africa, Italy and France during World War II, Leroy took a job as a maintenance supervisor in Los Angeles. He married a white clerk, Ella, who worked in the same school. The marriage of Ella and Leroy was a disappointment to both families, who would have preferred their children x. find partners of the same race. Ella was a Bronx native, the descendant of Russian immigrants. Unlike her husband, who died earlier this year, Mrs. Mosley is a private and serious per- son. "She was always the support for my father," Walter says. Her relatives were the few white people Walter knew well when he was growing up. Leroy and Ella's son, Walter, attended undergraduate school, then dropped out of the City College of New York graduate program in writing. He was employed as a computer pro- grammer when he started his first book, Gone Fishin', waking at 5 a.m. each day and writing until he left for work three hours later. Gone Fishin' traces the early lives of Easy and Mouse, two of his central char- acters from Devil in a Blue Dress and Red Death. Publishers were anything but hooked. ( (