Statutory Research

Statutes aren't always clear on their face. Language can be confusing and ambiguous, and it's hard to legislators to predict all of the scenarios that might arise under a given statute. There are certain rules of statutory construction and interpretation, and it's also vital to look for case law where courts have interpreted the statute. 

Here are a few resources addressing statutory construction and interpretation:

1. Secondary Sources: Secondary sources describe a legal issue and point you to major primary law that controls, including statutes and cases. 
2. Notes of Decisions: If you're working with a statute (say Mass. Gen. Laws ch. 266 §14, the armed burglary statute), use the Notes of Decisions on Westlaw & Lexis to lead you to cases that have interpreted said statute or court rule. These are selected by editors at West/Lexis.  
3. Citing References: Similar to Notes of Decisions → If you're working with a statute (say Mass. Gen Laws ch. 266 §14, the armed burglary statute), use Citing References to find all cases that have cited your statute or court rule. This is a broader group of cases that those selected by the editors to appear in the Notes of Decisions. 
4. AI Legal Research Tools: ChatGPT is pretty terrible at legal research—it will flat out make things up. But specialized AI tools like Lexis Protégé and Westlaw's CoCounsel are very useful, as long you remember to actually go read and verify what they say and that they are still good law (similar to secondary sources). And use the AI tools along with other methods in this list - not as your only tactic. 
5. Headnotes/KeyNumbers: Particularly on Westlaw, once you find a helpful case that interprets your statute, use the tools in the Headnotes from a known case to lead you to other similar cases. 

A good secondary source on your topic—ideally from your jurisdiction—will discuss and explain relevant statutes and the major cases that interpret the statute. Make use of the Secondary Sources / Secondary Materials entry points on Westlaw and Lexis; practice areas on Lexis Practical Guidance and Westlaw Practical Law; and practice centers on Bloomberg Law, among others. 

The goal: an on-topic secondary source (e.g., treatise, practical guidance, or legal encyclopedia) from your jurisdiction. If one doesn't exist, many national treatises (not focused on a particular jurisdiction) will provide leads to statutes and interpretive cases.  

WESTLAW:  Don't know what constitutes a "dwelling house" or a "dangerous weapon"? Use the tabs above the statute. Notes of Decisions are selected by editors and arranged by topic. Citing References include all cases (or secondary sources or whatever you're looking for) that have cited your statute or court rule. The case might discuss your statute or court rule in depth or cite it quite peripherally. Once you go into Citing References, you can then filter cases by jurisdiction, search within for certain terms, and so on. 

LEXIS: Don't know what constitutes a "dwelling house" or a "dangerous weapon"? Scroll down under the text of the statute to find the Notes to Decisions, which are selected by editors and arranged by topic. Additionally, you can use the Citing Decisions tab or Shepardize the document to find all decisions and other sources that have cited your statute. The case might discuss your statute in depth or cite it quite peripherally. Once you go into Citing Decisions, you can then filter cases by jurisdiction, search within for certain terms, and so on. 

Specialized legal AI tools like Lexis Protégé and Westlaw's CoCounsel are far better than regular generative AI tools like ChatGPT. A few tips:

• Treat the response as a secondary source that wasn't written by a human expert.
• Be sure to actually go read and verify the primary law that is included in the response (similar to other secondary sources)—these systems frequently fail to accurately capture what a case actually says or holds. 
• Use AI tools along with other methods in this list—not as your only tactic. 
• Think critically about your prompt, including the following: supply the relevant jurisdiction; state your goal and purpose in asking; provide material facts and background information; and refine with follow-up prompts. 

If you find a good case on Westlaw, use the tools in the headnotes to find similar cases. This includes: cases that cite your case for the proposition that is covered in that headnote (green arrows below), and cases that have been tagged with the same key number in West's topic and key number "outline" of American case law (green boxes). 

On Lexis, headnotes can lead to other helpful cases in similar ways. The "Shepardize–Narrow by this Headnote" link will pull up cases that cite your case for the proposition that is covered in that headnote. The "More Like This Headnote" link will pull up cases with similar language patterns.