Between 1986 and 1992, serial killer William Lester Suff murdered at least twelve prostitutes in Riverside, California. In 1995, a jury found that the unassuming-looking middle-aged man had picked up street walkers in his van, then strangled or knifed them, and proceeded to do unsettling things with their corpses. His conviction appeared to bring to a close a six year-long manhunt for the so-called "Riverside Prostitute Killer," wanted in connection with the slayings of 19 prostitutes.

To those who knew him, Suff, a stocky, plain-looking 44-year old, seemed to be a normal person. He was captain of his bowling team and had a girlfriend. He worked as a clerk in a Riverside County supply warehouse, filling county office orders for furniture and equipment. But to get his job, Suff had lied about not having a criminal past. In reality, he had been paroled from Texas prison where he had served 10 years of...