D.C. Code § 6-331.01
The Mayor of the District of Columbia is hereby authorized to provide such relocation services as he shall determine to be reasonable and necessary to individuals, families, business concerns, and nonprofit organizations which may be or have been displaced from real property by actions of the United States or of the government of the District of Columbia, except the District of Columbia Redevelopment Land Agency, such actions to include, but not be limited to, acquisition of property for public works projects, condemnation of unsafe and insanitary buildings, and enforcement of the laws and regulations relating to housing. The Mayor shall provide that such individuals and families so displaced shall be given the same preference with respect to vacancies occurring in housing owned or operated within the District of Columbia by federal or District of Columbia governmental agencies as is provided in § 6-301.07(b) [repealed]. The Mayor is authorized to make housing surveys in order to carry out this subchapter.
D.C. Code § 6-331.01