Preservation letter

Due to the dynamic and temporary nature of digital records, and because of the variability in the duration of time that records are retained by service providers, law enforcement agencies may issue a preservation letter under 18 U.S.C. §2703(f). Generally, no regulations pertain to the retention of records held by service providers. These records may be retained briefly or not at all. The use of a preservation letter or order will prevent these records from being destroyed.

Although this is a federal statute, State and local agencies can also use this document to preserve digital evidence. Although preservation requests have no legally prescribed format, usually a phone request followed by a faxed letter is sufficient.