How this lawyer used AI to help him win a $1.5 million case

• A lawyer defended a family whose children were wrongfully detained at the US-Mexico border.
• Joseph McMullen used an AI legal tool to present his arguments to a federal judge.
• McMullen won the case and partly credits the tool with helping him with citations and brevity.

Some lawyers continue to fall for made-up cases generated by artificial intelligence. Others are quietly finding ways to make the technology work for them.

Joseph McMullen, a San Diego civil rights and criminal defense attorney, is one of them. Last year, he said, he used AI-powered legal software to help him win a major case by sifting through evidence and making his filings more persuasive.

The case that led McMullen to rethink his tools started with a 9-year-old girl, a passport photo, and a border agent who thought something didn't add up.

In 2019, Julia, a fourth grader, and her 14-year-old brother, Oscar, rose early every weekday morning to cross the US-Mexico border to go to school. The siblings were born in the US but lived in a Tijuana border town, court records show. For local kids, the commute was as familiar as brushing their teeth.

They'd crossed the border many times without incident until March 18, when a US Customs and Border Protection officer noticed a dot on Julia's passport photo that looked like a mole she didn't have in person.

Julia was taken to a secondary inspection area and interviewed alone, which the court would later find violated the agency's policy on questioning children. In a lawsuit, the family alleged that border officers pressured her to claim she was her Mexican cousin.

The government denied any coercion and argued that the length of the children's detention was justified because Julia repeatedly identified herself as her cousin. A Customs and Border Protection spokesperson declined to comment.

Julia was detained for 34 hours, and Oscar for roughly 14 hours, before they were reunited with their mother.

Swearing off ChatGPT

As he built his lawsuit against Customs and Border Protection over the children's detention, McMullen, who runs his own law practice, turned to technology to interpret the evidence.

By early 2024, he had three federal civil trials in three months. Time was short, and help was scarce.

He approached tools such as ChatGPT with deep skepticism. In one of his early tests, the chatbot surfaced a case that seemed perfect — until he realized it didn't exist. "That was it. Never again," he said.

Barely a month went by without another story of a lawyer getting burned by bogus case law. Judges were catching on. A public database maintained by the legal data analyst Damien Charlotin lists 120 cases in which courts caught lawyers using fake or hallucinated citations. Most of the cases were in the US in the past 18 months.

Still, the idea of using AI stuck with McMullen. Unlike lawyers who lean heavily on case law, he spends most of his time combing through police reports, surveillance footage, transcripts, and emails, then figuring out what he has, what's missing, and what story the evidence tells.

He wondered how better tech could help him, like taking a metal detector to a haystack.

Get to the point

There was no jury in his trial against CBP, which meant US District Judge Gonzalo Curiel would make the decision.

That made written filings even more crucial. "It was important to make it as easy as possible for [Curiel] to get the information that I really wanted him to look at," McMullen said.

Another attorney recommended Clearbrief, a tool that integrates with Microsoft Word and lets lawyers link every factual claim to the underlying evidence. The plug-in recognizes citations using natural language processing and automatically generates links to relevant case law or documents.

When an attorney files a brief using Clearbrief, a judge or any recipient can open a hyperlinked version in Word or a browser. Each citation becomes interactive: Clicking on one pulls up the exact source text side-by-side with the brief, allowing the reader to verify claims faster without digging through exhibits or databases.

While preparing for trial, McMullen found a California unlawful detainment case that had resulted in a large damages award. To try to steer Curiel toward a similar judgment, he used Clearbrief to link an appellate brief from that case — buried deep in a district court docket — directly in his trial memo.

McMullen said being concise in briefs isn't just about saving time; it's a persuasive strategy in itself.

Effective advocacy, he said, isn't about "inundating a finder of fact with all the evidence," but presenting "the most important things that you need to know." (He's certain Curiel and his clerks were thorough in their review.)

"Being efficient with anyone's time is persuasive," he said.

Clearbrief and the competition

Lawyers can also use Microsoft Word to hyperlink text.

The Clearbrief difference, its founder and CEO, Jacqueline Schafer, said, is that it automatically creates the hyperlinks and checks the citations against databases such as LexisNexis and vLex Fastcase. The tool flags any mismatch between what the lawyer writes and what the source says.

Schafer said it speeds up drafting and reduces the burden on judges to confirm that every citation is accurate and not the product of an AI hallucination.

Clearbrief's client list includes law firms, courts, and legal departments with names such as Hogan Lovells, Microsoft, and the American Arbitration Association. The service starts at $200 a month per user for solo practitioners and small teams, with higher rates for larger organizations.

Westlaw and LexisNexis also offer tools to assist with legal research and drafting, but they don't affect how the final document appears to the court or recipient.

Another Clearbrief feature McMullen relied on was timelines. The tool turned over dozens of depositions and other records and created a case chronology, complete with hyperlinks to the source documents that support the dates and events shown in the timeline.

McMullen didn't submit the timeline in court — it was "maybe a thousand lines," he said — but he read it closely in trial prep to make sure he hadn't missed anything.

Better outcomes

Last year, Curiel ruled that CBP falsely imprisoned the siblings and was liable for the "intentional infliction of emotional distress" in the 2019 incident. Oscar's grades went down. Julia suffered from insomnia and nightmares. Their parents sought therapy for them both.

Curiel wrote in his decision that the government's conduct was "beyond the bounds" of what is "usually tolerated in a civilized community. " He ruled that the agency must pay the family $1.5 million in total damages.

The US government appealed the decision and then dropped its appeal.

Many legal tech startups promise lawyers they'll be able to take on more cases. For McMullen, the promise of AI isn't about churning through more cases so much as going deeper on the ones he has. He said he used the time he saved to visit Julia's family in Mexico.

"There are several aspects of the practice that are gratifying," McMullen said. But, "there's not a single person who says, 'I really love the tedium of formatting that table.'"

Have a tip? Contact the reporter via email at mrussell@businessinsider.com or Signal at @MeliaRussell.01. Use a personal email address and a nonwork device; here's our guide to sharing information securely.