By Kathryn Casey. Later retitled Evil Beside Her, and as a result this particular edition is rather rare. The Bergstrom case tends to come up in conversations about how a predator's intimate partner "couldn't know."
Not an especially well-kept PB: spine crack, rubbing to edges and an off corner on the front, a sticker on the back, and page toning. But it's a solid research copy that should give you some insight into how the genre was told and sold at the end of the last century.