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Case Law Research

This is a guide explaining how to do effective case law research using online and print resources.

Case Law Research Online

The Texas State Law Library provides access to several case law databases that will allow you to conduct case law research online. These databases are complex and can be intimidating, but knowing a few tips will allow you to locate cases relevant to your research in no time at all. This page will discuss a few things you should keep in mind when conducting case law research online: selecting the correct jurisdiction, how to build a search string using Boolean operators and connectors, and how to use the databases to verify that a case is still good law.

Constructing a Search String

How should I enter my search terms in a database?

Both of the research methods discussed on the previous page regarding Case Law Research in Print (using the key number system and using annotations and footnotes) will work in legal databases, but databases like Westlaw Next, Lexis Advance, and Fastcase also offer the ability to search using keywords and phrases.

You can search using natural language phrases such as "violations of Fourth Amendment rights," but you'll most likely find that you get more relevant results if you use a legal database's special search terms and filters. Most databases allow Boolean searching and also allow the use of additional terms and connectors to help you get more precise results. Creating a custom search string is a great way to conduct efficient case law resarch.

Boolean operators

Boolean operators are simple words and symbols that allow you to build powerful and precise searches. Inserting different Boolean operators between different parts of your search words will give you control over what is and is not returned in the search results. All of the online case law databases available through the Texas State Law Library accept search strings that use Boolean operators.

Operator Purpose Example
AND Indicates that you want only search results that contain both of the specified terms.

A search for employment AND discrimination will only return search results that contain both the word employment and the word discrimination.

In this case, the reason for using the AND operator is if you're only researching cases involving employment discrimination and aren't concerned with cases that discuss other aspects of employment law or cases where discrimination was not involving employment.

OR Indicates that you want search terms that contain either one of the search terms on either side - and it doesn't matter which one.

A search for landlord OR lessor returns search results that contain either one of those terms.

In this case, you may want to use the OR operator because landlord and lessor mean roughly the same thing and you're not sure which term a case might use. Using OR means that you will get both sets of results.

NOT Indicates that you want results with the first term but do not want results that contain the second.

A search for lease NOT residential will return results that contain the term lease but exclude everything that also includes the term residential.

A good use for the NOT operator is if you keep getting irrelevant search results that you'd like to weed out. In the example above, you may be looking for cases about commercial leases and want to exclude everything about residential leases.

" " Indicates that you want what's inside the quotation marks to be treated as an exact phrase

A search for "cease and desist" will return very different results from searching cease AND desist. The first one will return results that use the exact phrase cease and desist. The second one will only return results that have both words somewhere in the text - but there's no guarantee that they will be found together as in the phrase cease and desist.

( ) Indicates that you want the search string inside the parentheses to be processed first and then those search results to be plugged in the remainder of the search.  A good example for this is searching registration AND (vehicle OR automobile) if you didn't know whether a case would talk about car registrations using the term vehicle or automobile. The database will first run a search to find cases that use either the word vehicle or the word automobile. Using those search results, it will then process the rest of the search and return only the items that also contain the word registration.


Additional Connectors

Many legal databases allow the use of connectors outside of the basic Boolean set to allow users to make searches more precise. These include wildcard characters and proximity connectors.

Connector Purpose Example
! Indicates that you want results that contain all variations of the base word you've given. Searching for prosecut! will return search results that contain these words that are an expansion of the base "prosecut-" that was provided: prosecution, prosecutor, prosecuting, prosecute.
/s, /p Indicates that you want the search terms to appear in the same sentence or same paragraph.

A search of arrest /s warrant will return only results where arrest and warrant appear in the same sentence. You may use this search if you want to find cases where you're interested in how an arrest and a warrant relate to each other.

This operator uses the concept that the more closely two words appear with relation to each other, the more closely they may be related. 

/n Replacing the letter n with a number, indicates that you only want results where your terms appear within that number of words of each other. A search of burglary /3 vehicle will help you find cases where the words burglary and vehicle appear within 3 words of each other. This can be helpful if you would like search results specifically about the burglary of a vehicle, but are not sure how that may be phrased.


Databases Available Remotely

Texas residents may apply for a free library account to access select library databases remotely. If you already have a library account, you can use your username and password to log in. See the Electronic Databases page for a full list of databases. 

Databases Available at the Library

The library subscribes to several databases which are only available at library computers. Users will need to visit the library in person and sign up for a library account to access these resources.

Free Resources Online

While it is not possible to locate all opinions for free online at this time, there are an increasing number of resources available for certain jurisdictions and certain time frames. While federal appellate and trial level opinions are sometimes accessible, only state appellate opinions are available through free search engines. To locate state trial documents, it is usually necessary to contact the district or county clerk of the trial court directly. See this directory to locate clerks for particular counties, Texas Judicial Directory.

Please note that free sources tend to lack the added-value features of subscription databases such as citators and citing references. Free resources also have a less powerful search feature when you are looking for cases on a topic, rather than simply trying to locate a known citation.