Hi, I live in Mexico City, so a LA based organization is out of my range, but I think you can always ask your instructor where he was certified, and who trained him, so you can check it out. My instructor for instance studied for several years with the security chief of the israeli embassy in Mexico, so even when he don't have a diploma hanging on the wall, is something I was able to verify. Besides if you have ever practiced other combat system your experience can help to separate a good instructor from a bad one.
"I don't need to fight to prove I'm right"