BLIND FAITH<i> by Joe McGinnis (Signet: $5.95) </i>

Joe McGinnis has written what many people call--with more enthusiasm than concern for grammar--”a good read”: His account of a scandalous murder is as entertaining as any detective novel. The Marshalls of Toms River, N. J., were the ideal upper-middle-class family: Go-getter Rob was married to lovely Maria; they had a large house, a country club membership and three athletic sons. This idyllic life was shattered when Maria was murdered in a lonely park. As the story of her death unfolds, a very different picture of Rob Marshall emerges: He engineered the crime for the insurance money, so he could pay off his gambling debts and finance a new life with his vulgar mistress. Although he occasionally provides more background information than is really necessary, McGinnis grabs the reader’s attention in the first chapter and only relinquishes it 448 pages later. NBC recently announced plans for a four-hour dramatization of the book, to be aired in 1990.