18 U.S. Code § 2426 - Repeat offenders
(a)Maximum Term of Imprisonment.—
The maximum term of imprisonment for a violation of this chapter after a prior sex offense conviction shall be twice the term of imprisonment otherwise provided by this chapter, unless section 3559(e) applies.
(b)Definitions.—In this section—
(1) the term “prior sex offense conviction” means a conviction for an offense—