from memory...
From memory, there is no law that says you must have a registered handgun in California. Also no requirement that the gun be in your name. If you commit a crime with that gun, there is provisions for sentencing enhancements if the gun does not belong to you, depending on the crime committed. What may be a misdemeanor crime if you had the gun registered to you, may become a felony if it is not. Maybe some recent law has changed everything, so not certain about current status. They print gun laws faster than I can keep up.
I doubt any gun I have is registered in my name. Some of the "x" owners are deceased, several belonged to LEO's originally, but they have all been checked and are clear and not reported missing or stolen. Any guns I own were purchased before mandatory transfer registration laws were in effect. I doubt I will need to buy another again, so I will stay under the radar, and don't have any plans to register them and pay a $$ fee for the privilege......