At every successful interrogations and clues that the players can find in L.A. Noire gives experience points that allows Phelps to rank up.
In L.A. Noire, players can rank up to level 20. When a player reaches a certain rank, rewards such as oufits and vehicles can be unlocked. Below are the information in which it will tell you how experience points are awarded.
5 EXP Points are Awarded…
– Acquire a Single Film Reel
– Answer One Question Correctly
– Discover a Landmark
– Collect a DLC Hidden Shield
15 EXP Points are Awarded…
– Complete a Street Crime Case
Rank 3 – Sword of Justice Outfit
Rank 5 – 5 Hidden Vehicles Revealed
Rank 8 – Sunset Strip Outfit
Rank 10 – 5 Hidden Vehicles Revealed
Rank 13 – The Outsider Outfit
Rank 15 – 5 Hidden Vehicles Revealed
Rank 18 – Hawkshaw Outfit