18 U.S.C. § 16: Crime of violence defined

The term “crime of violence” means—(a) an offense that has as an element the use, attempted use, or threatened use of physical force against the person or prop­erty of another, or (b) any other offense that is a felony and that, by its nature, involves a substantial risk that physical force against the person or property of another may be used in the course of committing the offense.