Far-fetched and just plain dumb.
SPOILERS
The story takes place in and around a fictionalized version of Naperville, IL. The police force in this town are a bunch of doofuses, apparently. They miss that one of the murder victims was run over by a car rather than sexually assaulted. Then, they miss that another was beaten in the back of the head with a hammer, rather than a suicide. Yes, there are plenty of twists and turns, but they are all really dumb.