Last month, the U.S. Court of Appeals for the Second Circuit issued a significant decision in U.S. v. Ganias overturning a criminal tax evasion conviction because the government had retained electronically stored information (ESI) for too long after the execution of a search warrant and then improperly searched and used that ESI in a case unrelated to the warrant from which it was procured.1 The majority decision, authored by Judge Denny Chin, held that the government’s conduct violated the defendant’s Fourth Amendment rights and that the ESI should have been suppressed, and vacated the conviction.
The Initial Search Warrant
When executing a search warrant, the government does not always seize data sources such as hard drives or conduct on-site reviews for relevant ESI, but instead increasingly makes mirror images—identical copies—of those sources for later review. This allows the government to assure that it takes all relevant and responsive ESI—including metadata, native files, and any data that may be fragmented across the systems or drives—in a pristine state for methodical forensic examination and retrieval of all ESI responsive to the warrant. Once that ESI is segregated, however, the non-responsive ESI is not always destroyed or returned. Sometimes, as happened in Ganias, it is retained indefinitely.
