D.C. Historic Preservation Law. A project of the Georgetown Law Library, this website has links to historic preservation law sources, cases, and Mayor's Agent decisions.
FindLaw.Com Findlaw is a free resource for cases, statutes, forms, legal news, articles, podcasts and blog posts. Users can filter to specific jurisdictions under its "State Laws" sections. Here is the link to the section on the District of Columbia.
Google Scholar - Provides access to some full-text articles, as well as case law. Default is for articles, but cases can be retrieved by selecting the case law option, and then select the jurisdiction.
National Center for State Courts (NCSC) This site has links to state courts for each state and the District of Columbia. Search features include the alphabetical quick jump search, or scroll down through each jurisdiction. For D.C., links are provided to the Court of Appeals, Superior Court and a Court Structure Chart.
The Washingtoniana Collection (also The People's Archive) This is a special collection of the D.C. Public Libraries, and it contains materials from the late 18th century to the present. Materials are for reference use only and do not circulate.
Research Guides are very good comprehensive sources. Here are some guides from local law libraries: