Legal research is how you find and analyze the legal authorities needed to answer a legal question or support a legal argument. Whether you're working with statutes, court opinions, or scholarly commentary, knowing how to locate, evaluate, and organize these sources is a foundational skill for anyone studying law.
This section covers the types of sources you'll encounter, the step-by-step research process, major online tools, search techniques, and how to make sure your sources are still reliable.
Types of legal research
Legal research means identifying and retrieving the information needed to resolve a legal question. You'll work with different categories of sources, and understanding how they relate to each other is the first thing to get down.
Primary vs secondary sources
Primary sources are the law itself. These include constitutions, statutes passed by legislatures, case opinions issued by courts, and regulations created by administrative agencies. Primary sources carry binding authority, meaning courts must follow them (within the right jurisdiction and hierarchy).
Secondary sources are everything that explains, interprets, or comments on the law. Think legal encyclopedias, treatises, and law review articles. These are persuasive rather than binding. They don't create law, but they can help you understand it and point you toward the primary sources that matter.
Online vs print resources
- Online resources include databases like Westlaw and LexisNexis, government websites, and digital libraries. They offer speed, powerful search tools, and the most current versions of legal materials.
- Print resources are the physical books, journals, and reporters found in law libraries. They can be useful for in-depth reading and sometimes provide editorial context that digital versions lack.
For most research tasks, you'll start online. But don't write off print resources entirely, especially for historical materials or when you want to browse a topic area more broadly.
Free vs paid databases
- Free databases like Google Scholar and government websites (e.g., Congress.gov) give you access to a significant amount of legal material at no cost. The tradeoff is that coverage can be incomplete, and you won't get the editorial tools (headnotes, citator signals) that paid platforms provide.
- Paid databases like Westlaw and LexisNexis offer comprehensive collections, advanced search features, and built-in citator services. They're the professional standard, but subscriptions are expensive. Most law schools provide student access.
Steps in the legal research process
Good legal research follows a structured process. Jumping straight into a database search without a plan usually wastes time and misses important sources.
Identifying legal issues
- Read the facts and questions carefully. What happened, and what does the client (or hypothetical) need to know?
- Break the problem into discrete legal questions. A single scenario might involve contract law, tort law, and a constitutional issue all at once.
- Identify which areas of law apply: constitutional, statutory, regulatory, or common law (case-based).
Developing a research plan
Before you start searching, map out your approach:
- What jurisdiction applies? Federal, state, or both?
- What types of sources do you need? If there's a statute on point, start there. If the issue is governed by common law, case research comes first.
- What secondary sources might give you useful background? Starting with a treatise or legal encyclopedia can save time when you're unfamiliar with an area.
- How much time do you have? Prioritize the most important questions first.
Gathering relevant sources
Use online databases, library catalogs, and secondary source citations to locate both primary and secondary authorities. Effective search techniques (covered below) will help you find targeted results rather than sifting through hundreds of irrelevant documents.
Focus on the most authoritative and current sources. A recent appellate court opinion from your jurisdiction is far more valuable than a decades-old trial court ruling from another state.
Analyzing and synthesizing information
Once you've gathered sources, the real work begins:
- Read each source carefully and extract the parts relevant to your question.
- Assess each source's authority. Is this case binding in your jurisdiction? Is this statute still in effect?
- Look for patterns and conflicts. Do multiple courts agree, or is there a split?
- Synthesize your findings into a coherent analysis that connects the sources to your specific legal question.
Updating research results
Research isn't finished until you verify that your sources are still good law.
- Run each key case through a citator (Shepard's on LexisNexis, KeyCite on Westlaw) to check whether it's been overruled, reversed, or questioned.
- Confirm that statutes and regulations haven't been amended, repealed, or superseded.
- Search for any very recent developments that your earlier research might have missed.
This step is non-negotiable. Citing an overruled case is one of the most damaging mistakes a legal researcher can make.
Key primary sources
Primary sources are the authoritative pronouncements of law from government bodies. They form the backbone of any legal argument.
Constitutions and statutes
Constitutions establish the fundamental framework of government and individual rights at both the federal and state levels. The U.S. Constitution is the supreme law of the land, and any statute or regulation that conflicts with it can be struck down.
Statutes are laws enacted by legislatures (Congress at the federal level, state legislatures at the state level). For many legal questions, a relevant statute is your starting point. You'll need to read the statutory text closely and then look at how courts have interpreted it.
Case law and precedent
Case law consists of written opinions by judges resolving specific legal disputes. These opinions interpret statutes, apply constitutional provisions, and develop common law rules.
Precedent is the principle that courts should follow the rulings of higher courts in the same jurisdiction when the facts and legal issues are similar. This is also called stare decisis. A ruling from your state's supreme court is binding on all lower courts in that state. A ruling from another state's court is only persuasive, not binding.
Administrative regulations
Regulations are rules issued by executive branch agencies (like the EPA or SEC) to implement and enforce statutes. They have the force of law and often contain the detailed, technical requirements that statutes leave to agencies to fill in.
You can find federal regulations in the Code of Federal Regulations (CFR) and proposed rules in the Federal Register. States have their own administrative codes.
Legislative history materials
Legislative history includes the documents produced during the process of enacting a statute: committee reports, hearing transcripts, floor debates, and earlier versions of the bill. Courts sometimes look at these materials to figure out what the legislature intended when the statutory text is ambiguous.
Committee reports are generally considered the most authoritative type of legislative history because they explain the purpose and meaning of specific provisions.
Essential secondary sources
Secondary sources don't create law, but they're often the best place to start your research. They give you background, point you to key primary sources, and help you understand how different legal principles fit together.
Legal encyclopedias
Legal encyclopedias like American Jurisprudence (Am. Jur.) and Corpus Juris Secundum (C.J.S.) provide broad overviews of legal topics. They summarize leading cases and cite extensively to primary authorities.
These are most useful when you're entering an unfamiliar area of law and need a general orientation before diving into case law or statutes.
Treatises and hornbooks
Treatises are in-depth scholarly works focused on a specific area of law (e.g., Prosser on Torts, Corbin on Contracts). They're typically written by recognized experts and provide detailed analysis with extensive citations.
Hornbooks are a subset of treatises aimed at law students, offering clear explanations of legal doctrines. Both are valuable when you need to understand the nuances of a complex legal issue.
Law review articles
Law review articles are scholarly pieces published by law school journals. They're written by professors, practitioners, and students, and they often provide deep analysis of specific legal questions or propose new legal theories.
These can be especially useful for cutting-edge issues where case law is still developing or where you need to find arguments that haven't yet been widely adopted by courts.
Restatements of law
The Restatements are published by the American Law Institute (ALI) and attempt to clarify and organize common law principles across jurisdictions. There are Restatements for torts, contracts, property, and other major subjects.
Courts frequently cite Restatements, and some jurisdictions have adopted specific Restatement provisions as their governing rule. Still, Restatements are secondary sources and not binding on their own.
Practice guides and manuals
Practice guides are hands-on resources for lawyers working in specific areas. They typically include forms, checklists, sample documents, and step-by-step procedures for common legal tasks.
These are less about legal theory and more about practical application. They're jurisdiction-specific and help bridge the gap between knowing the law and actually using it.
Online legal research tools
Online platforms are where most legal research happens today. Knowing the strengths and limitations of each tool helps you choose the right one for the task.
Westlaw and LexisNexis
These are the two dominant commercial legal databases. Both offer:
- Comprehensive collections of federal and state primary sources
- Extensive secondary source libraries
- Editorial enhancements like headnotes and case summaries that help you quickly assess relevance
- Built-in citator services (KeyCite on Westlaw, Shepard's on LexisNexis)
They require paid subscriptions, which are expensive for practitioners but typically available to law students through their schools.
Bloomberg Law and Fastcase
- Bloomberg Law combines legal research with business news, analytics, and docket tracking. It's particularly strong for transactional and corporate law research.
- Fastcase offers a lower-cost alternative focused primarily on primary law. It has a clean, intuitive interface and is included free with many state bar memberships.
Google Scholar for case law
Google Scholar includes a large database of published court opinions, especially from federal and state appellate courts. You can search by keyword, track citations, and link to full-text opinions.
It's a solid free option for quick case searches, but it lacks the editorial tools, comprehensive coverage, and citator services of paid platforms. Don't rely on it as your only research tool.
Government websites for statutes
Official government sites provide free, authoritative access to statutory text:
- Congress.gov for federal legislation (current and historical)
- State legislative websites for state statutory codes and pending bills
- eCFR.gov for the electronic Code of Federal Regulations
These are the best places to verify the exact text and current status of a statute or regulation.
Effective search techniques
Knowing how to construct good searches will save you significant time and produce better results.
Keyword searching tips
- Use specific legal terms and nouns rather than general verbs. Searching "negligent misrepresentation" is far more effective than "when someone lies."
- Put exact phrases in quotation marks: "reasonable expectation of privacy"
- Think about how courts and legislatures actually phrase things. Legal language has its own vocabulary, and matching it improves your results.
Boolean operators and connectors
Boolean logic lets you control how search terms relate to each other:
- AND requires all terms to appear: copyright AND infringement
- OR captures alternatives: car OR automobile OR vehicle
- NOT (or the minus sign) excludes terms: bankruptcy NOT "chapter 13"
- Proximity connectors specify how close terms must be. On Westlaw, hearsay /s exception finds those words in the same sentence. Hearsay w/3 exception finds them within three words of each other.
Narrowing results with filters
Most databases let you filter results after your initial search. Common filters include:
- Jurisdiction (e.g., only federal courts, only a specific state)
- Date range (e.g., cases from the last 10 years)
- Source type (e.g., only statutes, only secondary sources)
- Practice area (e.g., criminal law, employment law)
Applying filters early prevents you from wading through irrelevant results.
Expanding queries with synonyms
If your initial search returns too few results, broaden it:
- Add synonyms or related terms using OR: "wrongful termination" OR "wrongful discharge"
- Use truncation symbols to capture word variations. On many platforms, neglig! retrieves negligence, negligent, negligently, and so on.
- Consider whether different jurisdictions use different terminology for the same concept.
Citators and updating research
Citators are tools that track the history and subsequent treatment of a legal authority. Using them is not optional.
Shepard's and KeyCite
Shepard's (LexisNexis) and KeyCite (Westlaw) are the two major citator services. Both allow you to:
- See the full procedural history of a case (appeals, remands, etc.)
- Find every subsequent case, statute, or secondary source that has cited your authority
- View editorial signals (colored flags or symbols) that quickly indicate whether a source has been treated positively, negatively, or questioned
Checking currency of sources
When you citate a case, you're checking whether it's still good law. Specifically:
- Has the case been reversed or overruled by a higher court?
- Has the legal rule it established been superseded by a new statute?
- Has subsequent case law narrowed or limited its holding?
For statutes, check whether the provision has been amended, repealed, or found unconstitutional.
Identifying negative treatment
Citators flag negative treatment with warning signals. For example, a red flag on Westlaw's KeyCite means the case is no longer good law for at least one point. A yellow flag means it's been questioned or distinguished.
Pay close attention to why a case received negative treatment. A case might be overruled on one issue but remain good law on another. Read the citing references to understand the specific impact.
Locating additional relevant authority
Beyond checking validity, citators are powerful research tools in their own right. By examining which cases have cited your source, you can:
- Discover additional authorities on the same legal issue
- Find cases that apply the same rule to different facts
- Filter citing references by jurisdiction, depth of treatment, or date to find the most useful authorities
Evaluating source reliability
Not all legal sources carry the same weight. Part of being a competent researcher is assessing how much to rely on any given source.
Authority and reputation
The most important factor is binding vs. persuasive authority. A decision from your jurisdiction's highest court on the exact legal issue is the strongest possible source. An out-of-state trial court opinion is far less authoritative.
For secondary sources, consider who wrote it and who published it. A treatise by a leading scholar published by a major legal publisher carries more weight than an anonymous blog post.
Timeliness and currency
Law changes. A case from 1985 might still be good law, or it might have been overruled three times since then. Always verify currency through citators and check for recent legislative changes.
More recent sources aren't automatically better, but you need to confirm that older sources still reflect the current state of the law.
Bias and objectivity
Secondary sources can reflect the perspective of their authors. A law review article by an advocacy organization may present a one-sided analysis. This doesn't make it useless, but you should recognize the perspective and look for sources that consider counterarguments.
Court opinions can also reflect judicial philosophy, which is worth noting when you're evaluating how broadly a holding might apply.
Relevance to research question
A perfectly authoritative source is worthless if it doesn't address your specific question. Evaluate relevance by considering:
- Does this source come from the right jurisdiction?
- Does it address the same legal issue you're researching?
- Are the facts similar enough to be applicable?
- Does it provide analysis or just mention the topic in passing?
Organizing research results
As your research accumulates, staying organized becomes critical. A pile of unstructured notes won't help you when it's time to write.
Note-taking strategies
Develop a consistent system for recording information from each source. For every case, capture the citation, key facts, the court's holding, the reasoning, and any useful quotes. For statutes, note the exact provision, its effective date, and how courts have interpreted it.
Use a standard template so you can quickly compare sources later.
Creating research outlines
Organize your findings into an outline that tracks the structure of your eventual analysis. Group sources by legal issue, and under each issue, note which sources support which points.
This outline becomes the skeleton of your legal writing. Building it as you research (rather than after) helps you spot gaps in your analysis early.
Using citation management tools
Tools like Zotero, Mendeley, or EndNote let you store, tag, and organize your sources digitally. You can save full bibliographic information, attach PDFs, and sort sources into folders by topic or issue.
These tools also help with formatting citations later, though for legal writing you'll still need to follow Bluebook or ALWD citation rules.
Summarizing key findings
Periodically step back and summarize what you've found so far. Write a short paragraph capturing the main conclusions, the strongest authorities, and any unresolved questions.
This habit keeps your research focused and prevents you from going down rabbit holes. It also makes the transition from research to writing much smoother.
Ethical considerations
Legal research carries real ethical obligations. These aren't abstract principles; violating them can result in professional discipline, court sanctions, or harm to clients.
Avoiding plagiarism
Always attribute words and ideas to their original source. If you quote language directly, use quotation marks and provide a citation. If you paraphrase, make sure you've genuinely restated the idea in your own words and still cite the source.
Patchwriting, where you rearrange or swap out a few words from the original while keeping the same structure, counts as plagiarism even if you include a citation.
Proper attribution practices
Legal writing follows specific citation formats. The two main systems are the Bluebook (used by most courts and law reviews) and ALWD Guide to Legal Citation. Both require precise formatting of case names, reporter volumes, page numbers, and dates.
Every factual claim and legal proposition in your writing should be supported by a citation. Readers need to be able to verify your sources.
Confidentiality of client information
When conducting research for a real client, you must protect confidential information. This means:
- Don't include client names or identifying details in database search queries if avoidable
- Store research materials containing sensitive information securely
- Don't discuss client matters with unauthorized people, even casually
Competence in legal research
Lawyers have a professional duty to provide competent representation, and that includes conducting thorough research. This means staying current with research tools and techniques, knowing when an area of law is outside your expertise, and seeking help or additional training when needed.
For students, building strong research habits now pays off throughout your legal career.