18 U.S.C. § 641 : US Code - Section 641: Public money, property or records

      Whoever embezzles, steals, purloins, or knowingly converts to his
    use or the use of another, or without authority, sells, conveys or
    disposes of any record, voucher, money, or thing of value of the
    United States or of any department or agency thereof, or any
    property made or being made under contract for the United States or
    any department or agency thereof; or
      Whoever receives, conceals, or retains the same with intent to
    convert it to his use or gain, knowing it to have been embezzled,
    stolen, purloined or converted - 
      Shall be fined under this title or imprisoned not more than ten
    years, or both; but if the value of such property in the aggregate,
    combining amounts from all the counts for which the defendant is
    convicted in a single case, does not exceed the sum of $1,000, he
    shall be fined under this title or imprisoned not more than one
    year, or both.
      The word "value" means face, par, or market value, or cost price,
    either wholesale or retail, whichever is greater.