The Overlook, by Michael Connelly is the thirteenth book in the Detective Harry Bosch series.
From Michael Connelly’s website:
“A doctor with access to a dangerous radioactive substance is found murdered on the overlook above the Mulholland Dam. Retracing his steps, Harry learns that a large quantity of radioactive cesium was stolen shortly before the doctor’s death. With the cesium in unknown hands, Harry fears the murder could be part of a terrorist plot to poison a major American city.”
I really enjoyed reading this book and look forward to reading more of this series.