Most case books used in law school edit and abbreviate court decisions. To get a sense of the case, find the entire opinion on WestLaw or another source for case law and read the case in its entirety, including all dissenting and concurring opinions. By reading the entire court decision, you will understand all issues presented in the case.
One important skill for proper case briefing is issue spotting. You must understand which legal issues are being raised in the case. Most court decisions pose more than one legal issue. The opinion will often set out the issues near the beginning of the case. Issues should be posed in a way that you can answer them with a simple yes or no. For example, the issue in a case regarding the search and seizure of a person's home may be posed: Is the police search of X's home protected under the Fourth Amendment of the U.S. Constitution?
Most cases that come before a court have many details and background facts. You must choose only those details that relate to the main issues raised in the case. These are the facts that you will include in your case brief.
The court may give many answers to many questions in its decision. Choose only the answers that relate to the issues that you have outlined in your case brief. Be sure to understand what the court is stating. For instance, if the case asks whether the police search is protected by the Fourth Amendment, the court could conclude that certain aspects of the search comply with the Fourth Amendment while other aspects do not. In such a case, you must make that distinction when describing the holding of the court in the case.