Casebook: Episode II - The Watcher follows its predecessor (Episode I - Kidnapped) as far as this style is concerned. Cutscenes typically have you walking alongside your partner as he discusses some aspect of the case with you. The camera used in filming these scenes has a wider viewing angle than what the game allows you to see, so you can move your point-of-view around the video a bit to give it a slightly more interactive feel, but you are still pretty restricted to watching the area the game wants you to, and the camera will walk wherever it wants.
The in-game aspects throw you into a few different small environments that feels like Google Maps Street View. The rooms are still photographs stitched together to form a 3D world that allows you some very restrictive movement. Walking around these rooms can be a bit tough, but that feels more like a control issue rather than graphics, especially since the transition between the different parts of the room is smooth, unlike the Myst-style transitions seen in Google Maps.
Audio keeps up the cop-drama feel with actors portraying detectives in a bit of an over-the-top manner (though I don't know if that was intentional). Besides the dialogue that seems a bit cheesy at times, the game's sound effects are fairly low-key and take care of the bare minimum.