Rockstar Games have announced its plans for downloadable content for its crime thriller L.A. Noire. Over the coming months it plans to release a number of DLC for both Xbox 360 and PlayStation 3.

The planned DLC consists of four unique cases, two detective suits and a collectible challenge. Xbox 360 Achievements and PlayStation Trophies will be available in each of the four cases.

"With its blend of real crime influences and noir atmosphere, L.A. Noire contains boundless potential for new stories and new cases," said Sam Houser, founder of Rockstar Games. "The four new cases are strong standalone stories that sit perfectly alongside the main game."

From today, Rockstar are offering players the chance to purchase the L.A. Noire Rockstar Pass, a new way to pre-order DLC, which gives players access to all seven paid DLC. Currently costing $10 on PlayStation Network or 800 MS points for the Xbox 360 ($12.00 and 960 MSP after the promo period), the pass allows gamers to get all DLC free as it is released on the PS3 and Xbox 360.

Also releasing today are the pre-order DLC cases "The Naked City" and "A Slip of the Tongue", priced at 320 MS Points, and The Badge Pursuit Challenge and the Sharpshooter/ Broderick detective suits to download for 160 Microsoft Points and 80 Microsoft Points, respectively. A free download on both PSN and Xbox Live is available today of the Chicago Piano machine gun.

Two new cases inspired by noir fiction and real-life crimes, "Nicholson Electroplating" Arson case (June 21, 2011) and the "Reefer Madness" Vice case (July 12, 2011) will be available for 320 points.

Members of the social club are also getting some love in the form of a free download of the Chicago Lightning Detective Suit.

Here's a full schedule for the DLC :

Chicago Lightning Detective Suit (Social Club only) - May 17

L.A. Noire Rockstar Pass (limited-time discount price) - May 31

"The Naked City" DLC case - May 31

"A Slip of The Tongue" DLC case - May 31

Broderick Detective Suit and Gun - May 31

Sharpshooter Detective Suit and Gun - May 31

The Badge Pursuit Challenge - May 31

Chicago Piano Machine Gun (free community unlock) - May 31

L.A. Noire Rockstar Pass (standard price) - June 14

"Nicholson Electroplating Disaster" DLC case - June 21

"Reefer Madness" DLC case - July 12.