Looking for clues
Give 'em a grillin'
You see, the City of Angels is populated by anything but angels. It seems almost everyone has something to hide: the director abusing the starry-eyed teenage hopeful on the casting couch, the philandering husband faking his own death to elope with his lover, the street vendor selling morphine taped to the undersides of popcorn boxes. Everyone's got an angle, and no-one's eager to assist you with your investigations.
Clue at the blue
Interrogation, therefore, is the pulsating heart of gameplay. Logic, intuition and evidence are all required to distinguish fact from fiction - often requiring you to backtrack and question people several times upon discovery of new evidence or leads - but it's the ability to read body language that really steals the show.
While falling short of the visual fidelity of Killzone 3 and Black Ops, the much-vaunted Motion Scan technology imbues facial animations with a range of expression unseen before. You'll need to scrutinise your witness or suspect for any signs of subterfuge, no matter how subtle. A nervous twitch, a chewed lip, or an aversion to your gaze can all cast doubt on statements. Call it right, and they'll spill the beans. Get it wrong, and they'll clam up and the line of inquiry will close.
If you suspect they're lying altogether, you're going to need to back up your assertion with hard evidence. It's here that LA Noire displays the gulf between real life and videogames. The logic is often highly subjective and littered with non-sequiturs, making inductive reasoning impossible. It's not quite Monkey Island logic, but even after amassing overwhelming evidence, choosing which to use to disprove a lie can be a frustrating guessing game.