The Scarecrow - Michael Connelly

Jack McEvoy is at the end of the line as a crime reporter. Once a hotshot in the newsroom, Jack is now in the crosshairs of the latest set of layoffs at the Los Angeles Times. He decides to go out with a bang, using his final days at the paper to write the definitive murder story of his career.
Jack focuses on Alonzo Winslow, a sixteen-year-old drug dealer in jail after confessing to the brutal murder of a young woman found strangled in the trunk of her car. But as he delves into the story, Jack realizes that Winslow's so-called confession is bogus. The kid might actually be innocent.
When Jack connects the L.A. trunk murder to an earlier murder in Las Vegas, he is off and running on the biggest story he's had since the Poet crossed his path years before. This time Jack is onto a killer who has worked completely below police and FBI radar–and with perfect knowledge of any move against him.