Trapper, what you're talking about is slightly different. Smartphones, especially iPhones, usually have a password/pin/bio-metric lock (your face, your fingerprint). The data on your phone is encrypted and cannot be read or accessed unless you put in the password/pin/fingerprint/etc. The shooter in the attack in question died, so obviously he cannot provide the info. If this was, say, a laptop, the FBI could just take out the hard drive and read it (since passwords to computers is usually to turn them on and data on them is usually not encrypted). Apple, as the creators of the encryption, has the ability to de-encrpyt it. But they chose not to, because once you make a master key....well, someone can get a hold of it, and open every lock. I do not like Apple at all and I honestly believe they did the right thing here.
The original question was about a photographer's camera, which is going to be an slr (d or otherwise). There are some dslrs that have on-device encryption (so it encrypts the pictures and then writes it onto the SD card/flash storage), but they have been compromised, so the feds can get to it. Even if the camera had some sort of password to turn it on, it doesn't stop the cops from opening the camera up, taking the sd card out and then sticking it into a computer to read. And if it's a film camera, well, nothing's stopping them from opening it up and developing the film themselves.
What you're talking about is ONLY going to be relevant if the "photographer" in question is going to be using an iPhone, but at that point it's probably not a professional photographer/journalist, but a private citizen. In journalism school we're taught media law so not only do we not get into hot water, we can make sure that the cops can't access our stuff, either. There are some specific laws/cases that are relevant to journalists knowing something that can't be obtained elsewhere, but if this is a regular photographer (like a wedding photographer or for models or ads or something) then those won't apply.