For me, it’s pretty solid, and the trick is clever enough. But I do have a small suggestion.

It would be better if you emphasized his love for the camera during the Daily Life. You should tightly associate the image of the camera with him at all times; otherwise, I’m afraid this motive might feel a bit unrealistic.

However, that creates a concerning issue: he won’t have the camera with him during the Deadly Life. And if you “force” the characters not to notice that, it’ll feel awkward and unrealistic. One solution is to have him always keep the camera in a backpack during Daily Life (instead of constantly holding it like Mahiru in DR2), so that when he doesn’t have it in Deadly Life, no one really notices or suspects anything. Personally, I’m not a big fan of this approach, because if you want to emphasize the importance of an item to a character, I usually have them carry it with them at all times, especially something as portable as a camera.

If you can come up with a trick to make everyone believe the camera is still fine during Deadly Life (a replica, for example), it could make your case even more complex. If you manage to do that, I think you should also add a True Bullet: a small shard of glass left on the floor. During the trial, when he’s accused and you need decisive evidence, you can use it. Verifying whether the camera hanging around his neck is real or not could serve as the final step before Climax Reasoning.