City of Whispers by Marcia Muller

When PI Sharon McCone receives an e-mail from her brother asking for help, it is the last thing she wants to do. Darcy Blackhawk is the black sheep of the family, a long list of faults, but she wants to reach out to him anyway. When she searches for him, not an easy task, an unsolved murder comes to light, a kidnapping takes place and people are dying. Determined, McCone plugs away, one clue leading to the next. Will she find Darcy before it is too late? Not a bad read.