The legal standing or authority of a case can change over time. A decision may be reversed on appeal or overturned years later by a decision of the same court. Other courts may criticize the reasoning of a decision or limit its holding to a specific set of facts. In any event, you need to know if the case you are citing as precedent is good law.
Case citation is nearly all done online using Lexis and Westlaw. The Hastings Library no longer subscribes to the print Shepard's case citator volumes.
Two Sources To Check If Case is Still Good Law:
1) KeyCite- Westlaw
KeyCite is West’s citation research service. It helps you determine whether a case, statute, administrative decision, or regulation is good law. You can also use KeyCite to retrieve citing references to the document, including cases, administrative materials, secondary sources, and briefs and other court documents.
(2) Shepardize- LexisNexis
The largest publisher of legal citators in the United States is Shepard's. Shepard's allows you to update case law, statutes, and other sources of law. Shepard's Citations publishes nearly 200 different citators and is available in print form (not commonly held by libraries anymore) and online through LexisNexis.
Keycite (video cast)
Shepards (video cast)
Westlaw- How to Keycite
LexisAdvance- How to Shepardize (video cast)