Citing a legal brief in APA:
Document name, pincite, case citation (docket number), commercial database identifier (if you accessed the brief through Nexis Uni, Westlaw, HeinOnline etc.).
If you didn't access the brief through a database, provide the retrieval statement — Retrieved from
------------------------------------------------------------------
Example 1:
Reference
Reply brief of petitioners Jennifer Gratz and Patrick Hamacher, Gratz v. Bollinger, 539 U. S. 244 (2003) (no. 02-516). Retrieved from http://supreme.findlaw.com/supreme_court/briefs/02-516/02-516-mer-pet-rep.html
In-text citation
Gratz v. Bollinger (2003) or (Gratz v. Bollinger, 2003)
Example 2:
Reference
Brief for Ringling Bros.-Barnum & Bailey Combined Shows, Inc. et al. as Amici Curiae Supporting Respondents, Mosely v. V Secret Catalogue, Inc, 537 U.S. 418 (2003) (no. 01-1015), 2002 WL 1987618.
In-text citation
Mosely v. V Secret Catalogue (2003) or (Mosely v. V Secret Catalogue, 2003)
Thanks to Concordia University's Ask a Librarian for this quick reference.