(a) Definitions. - In this section, the following definitions shall apply: (1) Crime of violence. - The term "crime of violence" has the meaning set forth in section 16. (2) Minor. - The term "minor" means a person who has not reached 18 years of age. (3) Uses. - The term "uses" means employs, hires, persuades, induces, entices, or coerces. (b) Penalties. - Any person who is 18 years of age or older, who intentionally uses a minor to commit a crime of violence for which such person may be prosecuted in a court of the United States, or to assist in avoiding detection or apprehension for such an offense, shall - (1) for the first conviction, be subject to twice the maximum term of imprisonment and twice the maximum fine that would otherwise be authorized for the offense; and (2) for each subsequent conviction, be subject to 3 times the maximum term of imprisonment and 3 times the maximum fine that would otherwise be authorized for the offense.