How to Use Claude for Legal Research Without Fake Citations

Claude is a good legal research assistant and a dangerous legal research source. Give it the jobs that need reasoning: framing the issue, breaking it into elements, planning the search and reading the authorities you paste in. Never let it supply a case, a statute or a quote from memory. Every authority goes through a primary source before it goes into a document.

Why is this the rule?

Because the failure is public and expensive. In Mata v. Avianca (S.D.N.Y. 2023), lawyers filed a brief citing cases produced by ChatGPT that did not exist, and the court sanctioned them. Similar incidents have followed in other courts. A citation has a predictable shape, so a model can produce one that looks perfect with nothing behind it. The workflow below is built so that cannot happen.

0:15 · loop 同樣的 AI，同樣的問題。一個檔案讓它成為專家。

Step 1: How do you frame the issue?

Most research time is lost before the first search, by researching the wrong question. Make Claude separate the facts from the legal questions.

You are helping me frame a legal research question. Do not cite any case, statute or regulation in this step. Jurisdiction: [STATE / COUNTRY, COURT LEVEL] Area of law: [e.g. commercial lease, employment, contract] Facts (anonymised): [FACTS] 1. State the legal question(s) in one sentence each, as a court would phrase them. 2. For each question, list the elements or factors that usually decide it, in plain terms. 3. List the facts that matter for each element, and the facts I have NOT given you that would change the answer. 4. Name the likely counter-arguments. Mark anything that depends on jurisdiction-specific law as [CHECK IN JURISDICTION].

Step 2: How do you plan the search?

Using the questions and elements above, write a research plan. For each question: - Primary sources to check first (type of source, not specific citations): statute, regulations, leading appellate cases, court rules. - 5 search strings for a legal database, using Boolean and proximity connectors where helpful. - Secondary sources worth reading for an overview (type only). - What a "good" answer would look like, so I know when to stop. Do not name specific cases. I will find them.
The skill this guide is built on
AI Legal Research Assistant for Claude and ChatGPT
AI Legal Research Assistant
$19this skill, one file or $9/moevery skill, Library

Takes a legal question or fact pattern and structures the research: relevant doctrine, the questions worth checking against primary sources, and an organised memo shell you fill with citations from your own research tools. It structures research; it does not replace Westlaw, Lexis or a licensed opinion.

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Step 3: How do you work with the authorities you found?

This is where Claude earns its place. Paste the actual text of what you found, and make it quote, not paraphrase.

Below are the authorities I found. Use ONLY these. Do not add any other case or statute. [PASTE STATUTE SECTION / CASE EXCERPTS, each labelled A, B, C...] For each legal question from step 1: 1. Which authorities apply, and the exact passage (quoted, with label) that supports each point. 2. Where authorities conflict, how a court in [JURISDICTION] would likely resolve it, and why. 3. Gaps: any element with no supporting authority, marked [AUTHORITY NEEDED]. 4. Points where my facts are weak. If you are not sure a passage supports a point, say so instead of stretching it.

The quote requirement is your verification shortcut. If Claude cannot quote the passage, the point is not supported by what you gave it.

Step 4: How do you turn it into a memo?

Ask for a memo shell in the format your office uses, built only from step 3. Our guide to Claude as a legal assistant covers citation format and jurisdiction checks in more depth, and the drafting side has its own guide in this series.

What should you never ask Claude in legal research?

  • "Find me cases that say..." It will find them whether they exist or not.
  • "Is this still good law?" It cannot check a citator and does not know recent decisions.
  • "What is the limitation period in [state]?" as a final answer. Use it as a starting point and check the statute.
  • Anything with client names or identifying facts that your rules do not allow you to share.

Need more than one specialist?

Legal work moves from research to drafting to review, and each stage has its own specialist. Library puts every skill, prompt pack and agent in the catalog (2,500+) inside Claude, ChatGPT, Claude Code, Codex or Cursor through one connector: you ask for a specialist by name and it loads. It is $9 a month or $59 a year, with a free trial, no card needed. Why a subscription beats buying files · See plans

How do you install a legal research skill in Claude?

A KissMySkills skill is a ZIP file with a SKILL.md at its root. In the Claude desktop app, open Customize → Skills, add a skill, upload the ZIP and toggle it on. Skills need code execution enabled, under Settings → Capabilities. If the Skills menu is not available on your plan, or you work in ChatGPT or Gemini, open the SKILL.md in a text editor and paste it into a Claude Project, a custom GPT or a Gemini Gem instead.

The other route skips files altogether: connect KissMySkills once and ask for the specialist by name in the chat you already use. That is how Library works, and it is covered in the box above.

In summary:

Frame the issue, plan the search, paste the authorities you found, and make Claude quote every passage it relies on. Never take a citation from memory. For the structure in one file, the AI Legal Research Assistant ($19). For a lawyer-focused overview of what Claude can do, see Claude for lawyers. Verification stays with you.

Skill · .md · Works with Claude & ChatGPTAI Legal Research Assistant for Claude and ChatGPT

AI Legal Research Assistant

Issue framing, research plans and a memo shell built only from authorities you verified. No invented citations by design.

$19
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Or every skill for $9/mo: try Library free, no card needed.

KissMySkills is a marketplace of 2,000+ AI skills, 100+ agents, 300+ prompt packs & free tools for Claude, ChatGPT & any AI chat. 30-day money-back guarantee.

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常見問題

Can Claude do legal research?+

Claude can structure legal research well: framing the legal issue, listing the elements to prove, suggesting search terms and reading statutes or cases you paste in. It should not be your source of authorities. Any case, statute or quotation it supplies from memory must be checked in a primary source such as Westlaw, Lexis, an official court site or a government legislation database before you rely on it.

Why does AI make up case citations?+

A language model generates text that looks plausible. A citation has a predictable shape, a party name, a volume, a reporter and a page, so the model can produce one that looks right without any real case behind it. In Mata v. Avianca (S.D.N.Y. 2023), lawyers were sanctioned after filing a brief with cases generated by ChatGPT that did not exist.

How do I stop Claude from inventing cases?+

Tell it not to cite any authority you have not pasted, and to mark gaps as [AUTHORITY NEEDED] instead. Then do the search yourself and paste the text of the cases or statutes you find. Ask Claude to quote the exact passage it relies on for each point, so you can check it against the source.

Is it confidential to put client facts into Claude?+

Check your professional rules and your firm's policy first. Remove names and identifying details where you can, and review the privacy and data retention settings of the plan you use. Team and Enterprise plans have different data terms from consumer plans.

Does AI replace Westlaw or Lexis?+

No. Research databases give you verified, current authorities and citators that show whether a case is still good law. Claude helps you plan the search and work with what you find. The two do different jobs.

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