A Tap on the Window by Linwood Barclay

Cal Weaver is a private investigator in upstate New York, whose life and marriage are in disarray because of his teenage son Scott's recent death.  When a local girl named Claire asks Cal for a ride, he starts to say no, but relents when she mentions that she knew Scott. Cal has no idea that his simple act of kindness will plunge him into the middle of a murder investigation, put himself in danger, and maybe even help him find out what really happened to Scott.  A Tap on the Window is a classic Barclay thriller, since it's centered around domestic issues and has a main character that the reader really feels compassion for.  It is, however, more leisurely-paced, than Barclay's last book, Trust Your Eyes, which is one of the best books I read last year.  Still worth a read...