The Golem of Paris-Jonathan Kellerman

Then he comes across the file for a gruesome unsolved murder that brings the two halves of his life into startling collision.
Finding the killer will take him halfway around the world, to Paris—the city of romance, but also of gritty streets, behind the lights. It’s a dangerous search for truth that plunges him into the past.

And for Jacob Lev, there is no place more frightening.

Jonathan Kellerman has long been known for his mastery of criminal psychology and his ability to create thrilling novels of nuanced drama and suspense. But in The Golem of Paris , he and Jesse Kellerman raise that suspense to a whole new level.