Whenever any person under twenty-one years of age has been arrested, charged with the commission of an offense punishable in any court of the United States or of the District of Columbia, and, after investigation by the Department of Justice, it appears that such person has committed an offense or is a delinquent under the laws of any State or of the District of Columbia which can and will assume jurisdiction over such juvenile and will take him into custody and deal with him according to the laws of such State or of the District of Columbia, and that it will be to the best interest of the United States and of the juvenile offender, the United States attorney of the district in which such person has been arrested may forego his prosecution and surrender him as herein provided, unless such surrender is precluded under section 5032 of this title.

The United States marshal of such district upon written order of the United States attorney shall convey such person to such State or the District of Columbia, or, if already therein, to any other part thereof and deliver him into the custody of the proper authority thereof.

Before any person is conveyed from one State to another or from or to the District of Columbia under this section, he shall signify his willingness to be so returned, or there shall be presented to the United States attorney a demand from the executive authority of such State or the District of Columbia, to which the prisoner is to be returned, supported by indictment or affidavit as prescribed by section 3182 of this title.

The expense incident to the transportation of any such person, as herein authorized, shall be paid from the appropriation "Salaries, Fees, and Expenses, United States Marshals."