Stephen Singular crashed out this sturdy account of Wichita's notorious BTK serial killer in the one year since the nondescript churchgoer Dennis Rader was arrested for slaughtering 10 Kansans from a sixth-grade girl he hung on a sewer pipe to the widowed grandmother he strangled in her bed between 1974 and 1991. (Rader entered a guilty plea and is serving a life sentence.) The nickname ''BTK'' stemmed from his practice of binding, torturing, and killing his victims, and Unholy Messenger is packed with lurid behind-the-murder tidbits gleaned from Rader's long, enthusiastic confessions. In Cold Blood this is not. Singular dwells at tedious length on fallout at Rader's Lutheran congregation while skimping on details of his youth. But the story of this nebbishy, balding family man and his appalling crimes requires little artistry to become powerful, scary reading.