Case law for the most part comes from appellate courts. The appellate courts may be intermediate courts or they may be the high court of that state or court system. For instance, there is an abundance of case law rendered by the U.S. Circuit Court of Appeals. Likewise, there is a wealth of decisions rendered by the United States Supreme Court.
The decisions of the appellate courts are contained within various bound volumes published by different law publishing companies. A written decision rendered by a United States District Court judge may be published in legal books known as the Federal Supplement (abbreviated F. Supp.).
Example: A decision rendered by a United States District Court judge is generally referred to by the name of the parties, e.g., Jones v. Smith, 317 F. Supp. 2d 820 (N.D.IL. 2004). That case would then be found in volume 317 of the Federal Supplement Second beginning on page 820. The parenthetical means that it is a decision from a United States District judge in the Northern District of Illinois, that was rendered in 2004.
NOTE: The volumes are put into series and when they reach a certain number, generally 999, the numbering begins again at one. That is why you will find a 2d or 3d in the citation.
Decisions rendered by a United States Circuit Court of Appeals are found in law books known as the Federal Reporter. For instance, a decision rendered by the United States Circuit Court of Appeals for the Ninth Circuit could be reported at 356 F.3d 121 (9th Circ. 2004). That citation means that the decision was rendered by the United States Court of Appeals for the Ninth Circuit in 2004 and can be found in Volume 356 of the Federal Reporter Third Series at page 121.
Decisions from the United States Supreme Court may be reported in three different reporting systems, all of which are published by different publishing houses. For instance, a decision from the United States Supreme Court would frequently be referred to as Jones v. Smith 535 U.S. 85, 125 S. Ct. 25, 159 L. Ed. 2d 125 (2004). That decision would be found in any one of those three volumes with the first volume being referred to as the United States Reporter, Case Law 23 Volume 535, page 85. That same decision can also be found in the Supreme Court Reporter, in Volume 125, page 25 and would also be found in the Lawyer’s Edition Second Series in volume 159, page 125. The year refers to the year when the decision was rendered.