Among the many legal eagles involved in the O.J. criminal case, it was the prosecutors who won big in the court of publishing. While Johnnie Cochran could barely get his Journey to Justice (Ballantine) on the national charts (it didn't make even a single showing on PW's nonfiction hardcover list), Christopher Darden enjoyed a 21-week run (six of those in first place) with In Contempt (ReganBooks). Now, evidently, it's Marcia Clark's time to shine. Her Without a Doubt made it to the lead spot after a little more than one week in the stores. Written with Pulitzer Prize-winning journalist Teresa Carpenter, the Viking title had a five-star sendoff: Clark was featured on 20/20 and did a one-hour interview on Oprah, a three-part Today interview and another three-parter on Entertainment Tonight. Other appearances included The Tonight Show and Live with Regis and Kathie Lee. In addition, the former prosecutor is on the last leg of a 13-city, four-week national tour; Viking reports that some 500 people have attended each of her signings. After two trips back to press, the book's in-print total is about 600,000.