https://storage.googleapis.com/snap-inc/privacy/lawenforcement.pdf

b. Logs of Previous Snaps, Stories, and Chats Snapchat retains logs for the last 31 days of Snaps sent and received, for 24 hours of posted Stories, and for any unopened Chats or those saved by a sender or recipient. The logs contain meta-data about the Snaps, Stories, and Chats, but not the content. 8 Process required for logs of previous Snaps, Stories, and Chats: This information is available pursuant to a court order under 18 U.S.C. § 2703(d) or a federal or state search warrant. c. Content In certain limited circumstances it may be possible for us to retrieve the content of sent Snaps. The reason we often will not be able to retrieve Snap content is that we delete each Snap from our servers once all recipients have viewed it. And even when a Snap remains unopened, it will be deleted 30 days after it was sent. Story content may be available for up to 24 hours, or until deleted by a user. Chat content will be available only if the sender or recipient chooses to save the Chat, or if the Chat is unopened. Even when a Chat remains unopened, it will be deleted 30 days after it was sent. Memories content may be available until deleted by a user. Process required for message content: A federal or state search warrant is required for requests that include message content.