(a)
Of a Minor.—
Whoever, in the special maritime and territorial jurisdiction of the United States or in a Federal prison, or in any prison, institution, or facility in which persons are held in custody by direction of or pursuant to a contract or agreement with the head of any Federal department or agency, knowingly engages in a sexual act with another person who—
(1)
has attained the age of 12 years but has not attained the age of 16 years; and
(2)
is at least four years younger than the person so engaging;
or attempts to do so, shall be fined under this title, imprisoned not more than 15 years, or both.
(b)
Of a Ward.—
Whoever, in the special maritime and territorial jurisdiction of the United States or in a Federal prison, or in any prison, institution, or facility in which persons are held in custody by direction of or pursuant to a contract or agreement with the head of any Federal department or agency, knowingly engages in a sexual act with another person who is—
(1)
in official detention; and
(2)
under the custodial, supervisory, or disciplinary authority of the person so engaging;
or attempts to do so, shall be fined under this title, imprisoned not more than 15 years, or both.