It is not easy to find a pro bono lawyer for a civil matter because the demand for them is so much greater than the supply. However, there are agencies which at the very least can walk you through what you have to do and advise you, even if they don't have the staff to be able to represent you themselves.
Here are some links to California's pro-bono resources.
Almost all of these agencies are for civil rather than criminal matters, and people in the pro bono loop usually know of still others who can assist you with your issue. So you may have to make a lot of phone calls, but you should be able to get at least some hands-on assistance.
Another thought is that you are in California, where there is a host of law schools. A good resource available for free or low priced legal assistance is law school clinics where law students research, write and handle actual cases and issues under the supervision of a practicing professor/lawyer. Some of these law school clinics have wonderful reputations, and if a court appearance is called for, the professor goes to court.
Law students are trained legal researchers. They are energetic, idealistic and enjoy putting their efforts into a cause they can believe in.
Here's a list of California Law schools. The kinds of clinics that they have are noted on the list: