The APA recommends following the Bluebook uniform system of citation for legal materials. The APA Publication Manual provides some information on citing legal sources in appendix 7.1 (page 216). For more in-depth information on citing legal materials, see The Bluebook: a uniform system of citation.
Commonly Cited Legal Documents
Name v. Name, Volume Source Page (Court Date).
Brown v. Board of Educ., 347 U.S 483 (1954).
Name of Act, Volume Source § section number (year).
Mental Health Systems Act, 42 U.S.C § 9401 (1988).
Title, # Cong. Session # (date).
Overprescribed: the human and taxpayers’ Costs of antipsychotics in nursing homes: Hearing
Before the Special Committee on Aging, United States Senate, 112th Cong. 1 (2011).
Start with the abbreviation U.S. Const., followed by the article, amendment, section, and/or clause numbers as applicable.