@NicoLyn,
No, it's as Lustig Andrei said. Someone with a practice in Century City would be a very successful lawyer, but with not much knowledge of criminal law.
The "it" refers to his having to lose his expensive membership (Riviera) if keeping it depended on his finding his way around a criminal proceding. The potential lawyer might be very competent in some areas of the law, but be lost in a criminal proceding.
Connelly is a good author to start with in learning a language, by the way. Entertaining stories, without using a lot of technical language. Anyway, it's not important to look up every unknown word. Just be sure you can follow the story, and the rest will mostly come to you.