Shakedown is a murder mystery, but the title isn't about extortion. It's about an unplanned career change. I really like this story, and it's free too.
Jack Davis is an FBI agent with a marriage that's dissolved, a daughter who is walking on the edge, and the shakes. He's doing his best to handle all three when a drug dealer he's pursuing is one victim in a mass murder and his shakes turn into a quake. Jack is suspended, but with the help of a jury consultant he's finds interesting in many ways, he may be able to clear this case before his career is shaken apart. This is as great mystery. Why pay for Connelly, Patterson, or Deaver when Goldman is free and just as good. Very highly recommended.