Outfits - L.A. Noire wiki

In game Outfits

Sword of Justice - Unlocked by reaching Rank 3

Golden Boy - Unlocked at the beginning of the Traffic Desk

Sunset Strip - Unlocked by reaching Rank 8

The Outsider - Unlocked by reaching Rank 13

Hawkshaw - Unlocked by reaching Rank 18 (Allows you to take more damage)

Chicago Lightning Suit (available through the Rockstar Social Club)

Pre-order outfits

The Broderick
Unlocked with downloadable content
Increased melee damage and damage taken

The Sharpshooter
Unlocked with downloadable content
Increased accuracy with the Garand and Colt .45

Button Man
Unlocked by collecting all DLC Hidden Shields
Carry Extra ammo for all weapons