Lights & Shadows - Aaron Wyler, #1

Following his wife's suicide, Aaron Wyler quits his job as a detective with the NYPD to focus on caring for his traumatized young son, but he soon gets pulled into investigating a strange death linked to a missing religious artifact, an ancient gemstone mentioned in both The Torah and The Bible. After a second murder, he stumbles upon a shocking conspiracy involving some of the world's most powerful and influential people.
In this first book in the Aaron Wyler detective series, Wyler is forced to confront dark forces he doesn't fully understand, including his own inner demons, in order to unravel a thrilling mystery from one of history's hidden footnotes.