Checking AI citations before you file

In 2023, a federal judge in the Southern District of New York sanctioned two lawyers and their firm in Mata v. Avianca, Inc. The lawyers had filed a brief citing court decisions that didn't exist. The cases, complete with plausible names, quotations and citations, had been produced by ChatGPT. When the other side and the court couldn't find them, the lawyers didn't promptly own up to what had happened.

The court imposed a $5,000 penalty and required the lawyers to send letters to their client and to the real judges who had been falsely named as authors of the fake opinions. The case made news well beyond the legal press, and it has been cited ever since as the example of what not to do.

It wasn't the last. Courts have continued to deal with filings containing citations that turned out to be fabricated or wrong, and some judges have issued orders about the use of AI in filings before them. Check the local rules and standing orders wherever you file.

Why AI makes this mistake

General-purpose AI chatbots are designed to produce likely-sounding text. They don't look cases up in a database the way a research service does unless they're specifically built to. Asked for authority supporting a point, a model can produce a case name, a citation in the right format and even a quotation, all invented, all looking exactly like the real thing.

That's why "the AI said so" can never be the last step. The duty of candor to the court (Rule 3.3 under the ABA Model Rules), the bar on frivolous claims (Rule 3.1) and Rule 11 in federal court all apply to what you sign, however it was drafted. ABA Formal Opinion 512 says the same about AI specifically.

A citation-checking routine

Use this for every filing, whether or not AI was involved. It's good practice either way.

1. Pull every authority from a reliable source

For every case, statute and rule cited, retrieve the actual text from an official source or a recognized research service. Not a summary, not a chatbot's answer, the document itself.

If you can't find it, it doesn't go in the filing.

2. Read the part you're relying on

Confirm that the authority says what the brief says it says. Check that:

• The proposition is actually supported, not just mentioned.
• Any quotation is word for word, with accurate pin cites.
• The holding isn't from a dissent, a concurrence or a part of the opinion that was reversed.

3. Check that it's still good law

Run every case through a citator to check subsequent history and treatment. A case that's been reversed, overruled or limited needs to be dropped or explained.

4. Check the citation format

Names, reporters, volumes, pages, courts and years should all be right. Errors here are often a sign something upstream went wrong.

5. Have someone else spot-check

On anything important, a second person checks a sample of citations independently. In a small firm, that might be a paralegal or another lawyer checking the five citations that carry the most weight.

6. Keep a record

A simple note in the file of who checked the citations, and when, is useful if questions ever come up.

If you use AI for research

AI can help with legal research when it's used carefully, for example to suggest search terms, summarize a case you've already pulled or organize an argument. Some practical rules:

• Prefer tools built on a legal database that link each citation to the actual authority. Even then, follow the routine above.
• Never cite a case you haven't read.
• Be careful with client information. Before putting confidential details into any AI tool, know whether it keeps or learns from what you enter.
• Write down your firm's policy on which tools can be used for research and what checking is required.

If you find a problem after filing

Correct it promptly. Courts have generally been far harder on lawyers who doubled down than on those who quickly acknowledged an error. Talk to your malpractice carrier and, if needed, ethics counsel.

Our approach

One of Meruit's product principles is no unverifiable citations, ever: when we build research features, case and statute citations will be checked against a licensed legal database before they're shown to you. Today, Meruit doesn't offer legal research. The same idea runs through what we have built: AI-suggested chronology entries carry a page citation and a quoted line, and Meruit checks the quote really appears on that page before showing it.