D.C. Mun. Regs. tit. 19 § 1407
No person, firm, association, or corporation owning or operating a video arcade or offering any mechanical amusement machine for public use shall permit any person under the age of sixteen (16) years to operate any of its machines between the hours of 8 a.m. and 3 p.m. on any day on which the public schools of the District of Columbia are in session during the regular school year. It shall be an affirmative defense to prosecution under this subsection that the defendant reasonably believed that the child was sixteen (16) years of age or older or that the child was not truant or unlawfully absent from school.
No person, firm, association, or corporation owning or operating a video arcade or offering any mechanical amusement machine for public use and allowing persons under the age of eighteen (18) years on the business premises shall sell, deliver, distribute, or provide any obscene, indecent, or filthy mechanical amusement machines displaying specified sexual activities or specified anatomical areas as defined in section 199 of the Zoning Regulations of the District of Columbia on the premises. It shall not be a defense to prosecution under this section that the defendant reasonably believed that the child was 18 years of age or older.
D.C. Mun. Regs. Tit. 19, § 1407