Echo Park is about Bosch investigating an old murder. A serial killer Raynard Waits had admitted that the did it.
That's also the base for story in Bosch Season 1.
It is good to read the book and find out the different between the books story and the TV stories.
The story progress like a movie, and you kind of feel bad for Bosch for being stepping on. He sound like a mature person who is willing to take quite a lot of risk in getting to the truth.
If you like quite a lot of details in things, then this book is for you. I like the way the description put you on the spot, and you see what Bosch see as it happen.
Fun read. Only a few more pages to go.