Legal research is structurally different from research in most other academic disciplines because its primary sources — statutes, case law, regulations, and constitutional provisions — are not scholarly interpretations of phenomena but the authoritative rules that govern conduct and the judicial opinions that interpret those rules. A student writing a law-related research paper must learn to locate, read, and analyze these primary legal materials in addition to engaging with the secondary scholarship (law review articles, treatises, and legal commentary) that interprets them. This guide, part of iResearchNet’s How to Do Research series, covers the databases, source types, free online tools, and citation conventions that U.S. college and university students need for research papers on law and legal topics. For topic ideas, see iResearchNet’s Law Research Paper Topics.
Understanding the U.S. Legal System’s Source Hierarchy
Before searching for legal materials, students should understand the hierarchy of legal authority in the United States, because a source’s position in this hierarchy determines its weight in a legal argument.
The U.S. Constitution is the supreme law of the land; any statute, regulation, or judicial decision that conflicts with it is invalid. Below the Constitution are federal statutes (laws enacted by Congress), which are codified in the United States Code (U.S.C.). Federal regulations — rules issued by executive agencies under authority delegated by Congress — are published in the Code of Federal Regulations (CFR) and announced in the Federal Register. Federal case law — judicial opinions interpreting statutes, regulations, and constitutional provisions — is produced by the U.S. Supreme Court, the U.S. Courts of Appeals (thirteen circuits), and the U.S. District Courts.
Each state has a parallel system: a state constitution, state statutes (codified in state codes), state regulations, and state courts (typically trial courts, intermediate appellate courts, and a supreme court). When a federal law and a state law conflict, the Supremacy Clause of the U.S. Constitution makes federal law controlling — but in areas where the federal government has not legislated, state law governs.
Understanding this hierarchy helps students determine which sources to search for. A paper on First Amendment free speech doctrine requires federal case law (primarily Supreme Court opinions). A paper on landlord-tenant law requires state statutes and state court opinions (because landlord-tenant law is primarily state law). A paper on environmental regulation requires federal statutes (the Clean Air Act, the Clean Water Act), federal regulations (EPA rules implementing those statutes), and federal case law interpreting both.
Legal Databases
Westlaw and LexisNexis
Westlaw (Thomson Reuters) and LexisNexis are the two dominant commercial legal research platforms, providing searchable access to virtually all published U.S. case law, statutes, regulations, law review articles, and secondary legal materials. Both platforms offer powerful search tools — including natural language searching, Boolean searching, and citation searching — along with citator tools (KeyCite on Westlaw, Shepard’s on LexisNexis) that allow researchers to determine whether a case has been overruled, distinguished, affirmed, or cited by subsequent decisions. Citator checking is essential in legal research because a case that has been overruled is no longer good law and cannot be relied on as authority.
Access to Westlaw and LexisNexis is typically available through university law libraries. Some universities provide access to undergraduate students through academic versions of these platforms (Westlaw Campus Research, LexisNexis Academic). Students should check with their library to determine what level of access is available.
HeinOnline
HeinOnline provides full-text, image-based access to more than 3,000 law journals and law reviews, making it the most extensive database for legal scholarship. Unlike Westlaw and LexisNexis — which also index law reviews but focus primarily on primary legal materials — HeinOnline specializes in secondary legal scholarship and provides page-image PDFs that reproduce the original published format (important for pin-cite accuracy in legal citation). HeinOnline also hosts historical legal materials, including the full text of the Federal Register from 1936, the Code of Federal Regulations, treaties, congressional hearings, and presidential documents. Most university law libraries and many general academic libraries subscribe to HeinOnline.
Free Online Legal Research Tools
Several free resources provide access to primary legal materials without requiring a subscription:
Google Scholar indexes both legal scholarship and case law. Its “Case law” search function provides access to federal and state court opinions and allows citation searching (identifying subsequent cases that cite a given opinion). While Google Scholar lacks the editorial enhancements and citator tools of Westlaw and LexisNexis, it provides free access to a large body of case law and is a useful starting point for students without access to commercial platforms.
CourtListener (Free Law Project) provides free access to millions of federal and state court opinions, oral arguments, and judicial financial disclosures. Its citation network tools allow users to trace how cases have been cited by subsequent decisions.
Justia provides free access to U.S. Supreme Court opinions, federal appellate and district court opinions, state court opinions, and state and federal statutes. Supreme Court of the United States maintains its own website with slip opinions, orders, and case information for recent terms.
Congress.gov provides the full text of current and recent federal legislation, including bill text, committee reports, floor statements, and voting records. For historical legislation and legislative history, the Library of Congress and GovInfo (Government Publishing Office) provide access to the Congressional Record, committee hearing transcripts, and earlier sessions of Congress.
The Legal Information Institute (LII) at Cornell Law School provides free access to the U.S. Code, the Code of Federal Regulations, Supreme Court opinions, and other primary legal materials, along with accessible overviews of major legal topics (the “Wex” legal encyclopedia).
Types of Legal Research
Statutory Research
Statutory research involves finding and interpreting the written laws enacted by legislative bodies. Federal statutes are organized by subject in the United States Code, which is divided into 54 titles covering different areas of law (Title 18 for criminal law, Title 42 for public health and welfare, Title 26 for the Internal Revenue Code, and so on). State statutes are similarly codified in each state’s code, accessible through the state legislature’s website or through Westlaw and LexisNexis.
Annotated codes — versions of the U.S. Code published with editorial notes, cross-references, and citations to cases that have interpreted each statutory provision — are essential research tools because they connect the text of the statute to the judicial decisions that have given it practical meaning. The United States Code Annotated (USCA, available on Westlaw) and the United States Code Service (USCS, available on LexisNexis) are the two major annotated versions of the federal code.
Case Law Research
Case law research involves finding and analyzing judicial opinions that interpret and apply statutes, regulations, and constitutional provisions. Case law is organized by court and jurisdiction: U.S. Supreme Court opinions are reported in the United States Reports (U.S.), federal appellate opinions in the Federal Reporter (F., F.2d, F.3d, F.4th), and federal district court opinions in the Federal Supplement (F. Supp., F. Supp. 2d, F. Supp. 3d). State court opinions are reported in state-specific and regional reporters.
Effective case law research typically begins with a secondary source (a law review article, a legal treatise, or a practice guide) that identifies the leading cases on a topic, and then proceeds to read those cases, check their subsequent treatment using a citator (to confirm they are still good law), and follow citations to related cases. Students unfamiliar with case law research should consult a legal research textbook or seek guidance from a law librarian — legal research involves conventions and techniques that are not intuitive to researchers trained in other disciplines.
Regulatory Research
Regulatory research involves finding and analyzing the rules issued by executive agencies. Federal regulations are codified in the Code of Federal Regulations (CFR), organized by title and chapter corresponding to the issuing agency. The Federal Register, published daily, contains proposed and final rules, notices, presidential documents, and agency guidance. For research on a specific regulation, the preamble to the final rule (published in the Federal Register when the regulation was adopted) explains the agency’s rationale and responds to public comments — this preamble is the regulatory equivalent of legislative history and is often essential for understanding why a rule takes the form it does.
Legislative History
Legislative history — the record of a statute’s development through the legislative process — is used to interpret ambiguous statutory language by examining what Congress intended when it enacted the law. Legislative history materials include committee reports (considered the most authoritative source of congressional intent), floor debates (published in the Congressional Record), hearing transcripts, and committee prints. These materials are available through Congress.gov, GovInfo, and through Westlaw and LexisNexis. Students should be aware that the use of legislative history in statutory interpretation is itself a contested question in legal scholarship — some judges and scholars (associated with textualism) argue that only the enacted text of a statute should be considered, while others (associated with purposivism) argue that legislative history illuminates the statute’s purpose and intended scope.
Law Reviews and Legal Scholarship
Law reviews — scholarly journals published by law schools and edited by law students — are the primary venue for legal scholarship in the United States. Unlike peer-reviewed journals in other disciplines (where articles are evaluated by faculty experts), law review articles are selected and edited by student editorial boards, though the authors are typically law professors, judges, and practitioners. Despite this unusual editorial structure, law review articles are widely cited by courts, legislators, and scholars and carry significant authority.
The leading general-interest law reviews include the Harvard Law Review, Yale Law Journal, Stanford Law Review, Columbia Law Review, University of Chicago Law Review, and Michigan Law Review. Specialized law reviews cover specific areas: the Journal of Criminal Law and Criminology (criminal law), the Georgetown Law Journal (procedure and federal courts), the Virginia Environmental Law Journal (environmental law), the Harvard Civil Rights-Civil Liberties Law Review (civil rights), and hundreds of others. HeinOnline provides the most extensive full-text access to law review literature.
Students should also be aware of legal treatises and practice guides — multi-volume works that provide systematic treatment of entire areas of law. Treatises like Wright & Miller’s Federal Practice and Procedure (civil procedure), LaFave’s Search and Seizure (Fourth Amendment law), and Corbin on Contracts are authoritative secondary sources that synthesize case law and statutory materials within a given field.
Legal Citation
Legal scholarship in the United States uses the Bluebook citation system (formally, The Bluebook: A Uniform System of Citation), which provides standardized formats for citing cases, statutes, regulations, law review articles, and other legal materials. Bluebook citation is substantially more complex than APA, MLA, or Chicago citation because legal sources are more varied in type and because precise citation (including specific page numbers — called “pin cites”) is required for legal authority.
A standard case citation includes the case name (italicized), the volume number, the reporter abbreviation, the first page of the opinion, the specific page cited, the court, and the year. For example: Brown v. Board of Education, 347 U.S. 483, 495 (1954). A standard statutory citation includes the title number, the code abbreviation, the section symbol, and the section number: 42 U.S.C. § 1983.
Students writing law-related papers for non-law courses should check whether their instructor expects Bluebook citation or a more general citation style (Chicago, which includes guidance on citing legal materials, is the most common alternative). Law courses and law school assignments almost always require Bluebook citation.
Professional Associations and Resources
The American Bar Association (ABA) is the primary professional association for lawyers in the United States and publishes the ABA Journal, legal practice resources, and policy reports on the justice system. The American Association of Law Libraries (AALL) provides resources on legal research methodology, and many AALL member libraries offer research guides and tutorials that are available online at no cost.
The American Law Institute (ALI) publishes the Restatements of the Law — influential secondary sources that synthesize and distill the common law on major subjects (contracts, torts, property, agency) into concise, authoritative statements. While Restatements are not binding law, they are frequently cited by courts and are essential research sources for papers on common-law subjects.
For interdisciplinary law-and-society scholarship, the Law and Society Association publishes the Law & Society Review, and the American Society of International Law publishes the American Journal of International Law. These journals bridge legal scholarship and social science research and are particularly relevant for students approaching law topics from a political science, sociology, or international relations perspective.
Interdisciplinary Legal Research
Many law-related research papers at U.S. colleges and universities are written not for law courses but for courses in political science, criminal justice, history, sociology, public policy, or business — fields where legal questions intersect with broader social, political, and economic analysis. Students writing law-related papers in these disciplines face a distinct challenge: they must engage with legal materials (statutes, cases, regulations) that follow conventions different from those of their home discipline, while also meeting the analytical expectations of their course.
Several practical principles help bridge this gap. First, secondary sources that synthesize legal materials for non-specialist audiences — including law review articles, legal treatises, Congressional Research Service reports, and the Legal Information Institute’s topical overviews — are often more productive starting points than primary legal materials, because they identify the key statutes and cases and explain their significance in accessible language. The student can then turn to the primary sources that the secondary source identifies as most important.
Second, students should recognize that legal reasoning follows a specific analytical structure — identifying the applicable rule (from a statute, regulation, or case), applying that rule to specific facts, and reaching a conclusion — that differs from the analytical structures used in the social sciences or humanities. A political science paper analyzing the Supreme Court’s equal protection jurisprudence, for example, should demonstrate understanding of the legal standards the Court applies (rational basis review, intermediate scrutiny, strict scrutiny) even if the paper’s ultimate argument is about political ideology rather than legal doctrine.
Third, empirical research on law — studies that use quantitative or qualitative methods to examine how legal rules operate in practice — draws on both legal and social science databases. The Inter-university Consortium for Political and Social Research (ICPSR) archives datasets on judicial behavior, sentencing patterns, litigation outcomes, and legal system operations. The Federal Judicial Center publishes research on the federal courts, including data on caseloads, case processing times, and judicial administration. The Supreme Court Database (maintained at Washington University in St. Louis) provides detailed data on every Supreme Court case since 1946, including vote breakdowns, legal issues, and case outcomes — an indispensable resource for quantitative research on the Court.
For research on comparative and international law, the United Nations Treaty Collection provides the text of international treaties and conventions. The International Court of Justice publishes its opinions and advisory opinions online. The European Court of Human Rights database (HUDOC) provides searchable access to the Court’s case law. The World Legal Information Institute (WorldLII) aggregates legal materials from jurisdictions around the world, providing a starting point for comparative legal research.
Frequently Asked Questions
Do I need access to Westlaw or LexisNexis to write a law paper?
While Westlaw and LexisNexis are the most powerful legal research tools, students can write effective law research papers using free resources. Google Scholar (case law search), CourtListener, Justia, the Legal Information Institute (LII), and HeinOnline (through library subscription) collectively provide access to case law, statutes, regulations, and law review articles. The main limitation of free tools is the absence of citator functionality — students using free resources should verify that cases they cite have not been overruled by checking subsequent case law through Google Scholar’s citation search or CourtListener’s citation network.
How do I read a court opinion?
A court opinion typically includes a statement of facts (what happened), a procedural history (how the case reached this court), the legal issue or issues presented, the court’s analysis (the reasoning that leads to the conclusion), and the holding (the court’s rule or decision on the legal issue). Students should focus on the holding and the reasoning that supports it, as these are the portions of the opinion that constitute binding legal authority. Concurring opinions (agreeing with the result but for different reasons) and dissenting opinions (disagreeing with the result) are not binding but can be useful for understanding alternative legal arguments and for predicting how the law might evolve.
Can I cite a court case in a non-law course paper?
Yes — court cases are legitimate and often essential sources for research papers in political science, criminal justice, history, public policy, and other fields that engage with legal questions. When writing for a non-law course, students should use the citation format required by the course (typically APA, MLA, or Chicago) rather than Bluebook citation. All three major citation styles include guidance on citing legal materials, though the formats differ from Bluebook conventions. Students should provide enough information for the reader to locate the case: case name, volume and reporter, first page, court, and year.
Where do I find state laws and court decisions?
State statutes are typically available through each state legislature’s website and through the Legal Information Institute (which links to all fifty state codes). State court opinions are available through Google Scholar (case law search), CourtListener, Justia, and individual state court websites. For students with library access, Westlaw and LexisNexis provide the most complete collections of state statutes and case law, with citator tools that show whether a statute has been amended or a case has been overruled.
Related Pages
- How to Do Research — Overview of research methods and discipline-specific guides
- How to Do Research on Criminal Justice — Databases and methods for criminal justice research
- How to Do Library Research — Using catalogs, databases, and librarian expertise
- Law Research Paper Topics — Topic ideas for law research papers
- How to Write a Research Paper — Complete step-by-step guide