Hieronymus Bosch is also the main character in a number of Michael Connelly murder mysteries, including The Black Echo, The Black Ice, The Concrete Blonde, A Darkness More Than Night (my favorite, of the admittedly few I've read), City of Bones, Angels Flight, Trunk Music, and The Last Coyote. I believe that's all that are currently out, though not necessarily in the order written.
Going mostly by the name Harry, Bosch is named after the artist, whose work plays a role in A Darkness More Than Night.
Most of Connelly's work consists of Bosch mysteries, though he has written a few others, including Void Moon and Blood Work (which is currently (2002) being made into a movie starring Clint Eastwood).
Bosch is an LAPD detective who has a severe distaste for authority; when we meet him in The Last Coyote, he has just been suspended from the force and sent to a psychologist for throwing his boss though the window in the front of his boss's office.