The keeping notes / comparing notes gameplay reminded me of one of my favourite childhood games, Activision's "Murder on the Mississippi" (1986).
I trust that "L.A. Noire" is way more sympathetic than "Murder" was; you could progress thru "Murder" collecting evidence and keeping notes and make it very close to the end of the game but never be able to finish it because of some note that you wrote down wrong. I am interested to see how the game plays out if you are just a terrible detective. Does the "Case" restart for you, or allow you to make a certain # of mistakes before it restarts? Or is it just GAME OVER, YOU SUCK.
I loved seeing actual gameplay from "L.A. Noire". It's the first footage to convince me that I need to buy this game and help me forget about how bored I was with the original "Mafia" game (PC 2002; XBOX 2004). Mind you I only played the XBOX version.