While the pacing does help build the suspense, I really think the book could have been fifty pages shorter. I know the author was trying to give the reader a sense of the town, but honestly, at some point you just want to know who the killer is. And it took forever. By halfway through the book only one girl had gone missing.
The book starts with a prologue describing the room in which the girls' bodies are found. It sets a gloomy mood for the rest of the book. As each of the three girls go missing, you read about the parents and town members searching and praying for the girls' return, but you know the truth. The girls are dead, tied to chairs in someone's attic, dressed in weird decorated robes, surrounded by melted candles. It's the "church" of the title, and it's a very creepy mental image. The most suspenseful part of the book is wondering if Sadie, the young girl whom the narrator lives near, is going to be one of the dead girls.
The book really spends most of its nearly 400 pages describing how the anxieties and suspicions of a small town grow and grow. At first everyone assumes that it must be someone from outside of Aurelius, because certainly none of their friends or neighbors could have done it. As each successive girl disappears, the townspeople become more and more suspicious of anyone whom they perceive as different. It's really a great examination of how a small town turns on its own members. And the big reveal in the last few pages was definitely unexpected. I found myself thinking "how on Earth did these people live with this psycho and not suspect something was up?" And then I remembered that I live in a small town where a three-year-old was stolen out of her own home and murdered, and the president of our library board was convicted of possession of child pornography in Canada. Those incidents are unrelated, btw. There are evil people everywhere, even if you don't suspect them. Terrible things happen all the time. I mean, Criminal Minds has to get its plot ideas from somewhere, right?