As I am not a CA lawyer, I'd expect Frank to know much more about this than I do. With that
caveat, I'll take a small stab at this one. Let me also point out that I have done ZERO research on the case law. Accordingly, take my comments for being worth exactly what you paid for them. Let me also point out that the automobile is the worst thing that's ever happened to the Fourth Amendment, IMHO.
To put it mildly, I have some very serious reservations about the constitutionality of 25850(b) in that it legislatively authorizes warrantless searches, even where there is no evidence of any criminal activity. Overlooking Section 25850 for the moment, I would suggest that the mere presence of a firearm in a locked case in the trunk, in and of itself, does not constitute probable cause for a search.
However, that fact is unlikely to ever come alone. For example, if running the driver's information through the SCMODS (State, County, Municipal Offender Data Systems
) turns up that the driver is a felon, we've got a different ballgame. If the driver matches a description of an armed robber that just went out on a BOLO, different ballgame.
Turning to the question with 25850 in mind, my first question is whether a driver is required to notify LE of the presence of a weapon that is in a locked case in the trunk. For example, if I tell the officer, "I have an unloaded gun in a locked case in the trunk of my car," 25850(b) purports to allow the officer to examine my firearm, even though they have no evidence that it is loaded. If I refuse to allow examination, even though the officer has no warrant and no probable cause that I have committed any crime, that refusal is grounds to have me arrested. . . IOW, if I assert my Fourth Amendment right, I get a shiny new pair of bracelets for a while. If I am
required to notify LE of the existence of same pistol, the problem is compounded. In that situation, in order to remain totally law-abiding, I must: (1) notify LE of the gun; and (2) submit to a warrantless (& possibly unconstitutional) search.
Naturally, if I refuse to allow the search, I will be arrested and my car impounded. At that point, as basilisk4 notes, the police will conduct an inventory search.
As a final note, criminal law is generally a matter of State law, as is most of the law surrounding searches and seizures by LE. One would be very, very ill advised to consult an Arkansas attorney for questions related to CA search and seizure law. It's a different state, in a different federal circuit. There's a whole slew of 9th Circuit and CA (state) Supreme Court case that I haven't even looked at in formulating the answer above. I am a lawyer, but I'm not a CA lawyer. . .