Justice Manual § 9-112.150

A seizing agency may commence a forfeiture proceeding as a criminal forfeiture (i.e., by seizing the property with a criminal seizure warrant under section 853(f)) and subsequently convert the proceeding to an administrative one without reseizing the property or taking some other action under the civil forfeiture statutes. Except in extraordinary circumstances, if the Government desires to commence administrative forfeiture proceedings against property seized pursuant to a criminal seizure warrant, it should do so within 60 days of the seizure. If the 60-day deadline has passed, and the Government still desires to pursue the forfeiture civilly instead of criminally, the case should be referred to the U.S. Attorney to commence a civil judicial proceeding. For additional information on this topic see Chapter 2 of the Asset Forfeiture Policy Manual ("Seizure Pursuant to a Criminal Warrant: Availability of Administrative Forfeiture").