How NIEM can be develop with CAM and how NIEM is associated with JSON?

JSON is nothing more than a rendering and fully supported by libraries such as the Apache Java XML2JSON library we are using - bi-directional seamless transforms.
There is nothing need to do here.  NIEM does JSON, and JSON does NIEM, and its completely interchangeable.  CAM demonstrates that as a reference implementation and anyone else can easily do this too.

CAM Reference Link: