District of Columbia Code Division V. Local Business Affairs § 32-1331.10. Retaliation prohibited.

(1) Makes an oral or written complaint with the employer or the Mayor alleging that the employer violated any provision of this subchapter or any rule issue pursuant to this subchapter;

(2) Brings an action or initiates a proceeding involving a violation of this subchapter;

(3) Testifies in an action authorized under this subchapter or a proceeding involving a violation of the provisions of this subchapter or any rule issued pursuant to this subchapter; or

(4) Assists in an investigation by providing information to a litigant in a civil action, the Mayor, or another agency in proceedings as provided by subchapter.

(b)(1) A person who believes that an employer has discriminated in any manner or taken adverse action against the person in violation of this subchapter may submit to the Mayor a written complaint, signed by the complainant, that alleges the discrimination.

(2) Upon receipt of a complaint, the Mayor shall conduct an investigation.