AI is already changing the practice of law, attorneys say
In 2019 a metal cart rolled down the aisle of an Avianca flight from El Salvador to New York and struck Roberto Mata on the knee. Mata retained two personal injury lawyers to sue the airline, resulting in a case that made legal precedent—but not for a reason Mata or his attorneys would have hoped for. Instead, the two lawyers achieved notoriety in 2023 when the judge in the case fined the pair $5,000 for citing six fictitious cases, invented by artificial intelligence software, in a brief to the court.
The punishment was the first of its kind and was widely reported in legal circles as a cautionary tale for lawyers about the risk of relying on AI. That cautionary tale has not been heeded. In the two years since the incident, there have been no fewer than 139 instances of legal briefs containing AI-invented citations—including over 30 this May alone. While many of these came from self-represented litigants, they also include briefs filed by prominent national law firms. And, in one instance, a judge struck expert testimony submitted by a data scientist from AI giant Anthropic—on the grounds it contained a “hallucination” created by Anthropic’s own software.
These stories of AI gone wrong in the courtroom make for a lively source of chatter around law firm watercoolers. Yet these cases are also outliers. In reality, the vast majority of lawyers using AI are doing so in responsible fashion—including by verifying that AI-produced citations actually check out before putting them before a judge.
Many are also delighted by how useful it is. Lawyers say AI excels at research and document review and that, more recently, they have found it to be capable of more challenging tasks like drafting legal briefs. And all of this progress has big implications for both the future trajectory of legal careers and for the business of law.
A growing suite of AI tools
Most lawyers came to appreciate the transformative power of AI at the same time as everyone else: November 2022. That was when OpenAI released the initial version of ChatGPT to the general public, and, unsurprisingly, it was about six months later that the first wave of fake citations began showing up in courtrooms.
In fact, the idea of using AI to inform legal research has been around for over a decade. Pioneers in the field include the likes of Ironclad and DISCO, which respectively offer automated ways to create and manage contracts and to expedite the discovery process.
The difference today is that, as in other industries, the past three years have seen the legal profession acquire and deploy AI tech at a broader and faster pace than ever before—especially as generative AI has become more easily available and more powerful.
In February, the Federal Bar Association published a survey of over 2,800 legal professionals: 21% said they used AI in their practice in 2024, and the number was significantly higher—39%—for attorneys at large law firms. A separate attorney survey published in April by the legal transcription service Rev found much higher overall adoption, with 48% of respondents saying they used AI for research.
Unsurprisingly, the number of AI offerings aimed at the legal profession is growing. There are services like Harvey, which is built on top of AI models from companies including OpenAI, Anthropic, and Google and specializes in drafting and research; and Vancouver, British Columbia–based Clio, which offers practice management tools. Clio raised $900 million in 2024, valuing the company at $3 billion; in late June, Harvey raised $300 million in a funding round that values the company at $5 billion.
For now, there is no clear data on how widely the lawyers deploying AI in their jobs are using these specialized tools, or if they are instead relying on popular LLMs created by the likes of OpenAI and Google, which have all ingested reams of common-law statutes and decisions.
According to Mark Lemley, a Stanford intellectual property professor well versed in legal tech, most law students and junior lawyers are likely using general services like ChatGPT, since those are the most accessible.
In large firms, a popular AI tool is CoCounsel, which was developed by the legal startup Casetext. The data giant Thomson Reuters purchased Casetext in 2023 and now offers CoCounsel as part of Westlaw, a popular but expensive service widely used by so-called Big Law firms.
Daryl Landy, a litigator with the national firm Morgan Lewis, says he likes CoCounsel in part because it is designed to take account of the legal profession’s special obligations regarding client confidentiality and data protection. In practice, this means that AI prompts created by Landy and his colleagues do not become part of a training set that can inform the research of people outside his firm—an important issue in a profession in which practitioners often have access to highly sensitive information about their clients.
Changing professional norms
For decades, most law firms have fit neatly into the “finders, minders, and grinders” model. The phrase describes a pyramid structure where a handful of rainmakers at the top bring in clients and hand over the bulk of the work to a second tier of senior lawyers, who in turn oversee a larger pool of associates.
Where does an AI agent fit into the pyramid? It’s been obvious for some time that AI is a good fit to displace large swaths of mundane “grinder” work—and indeed that is occurring with tasks like document review, contract drafting, and basic research. This is a good thing in many respects. AI is already eliminating some of the drudgery of legal work, much of which has traditionally come about in pursuit of billable hours—a notorious aspect of the profession that often leaves clients wondering how many hours on an invoice represent busywork rather than indispensable tasks.
In this light, it’s hard to argue with a technology that vastly reduces time spent on tedious tasks, reduces costs, and promises to free up lawyers for deeper and more strategic matters. Still, there are drawbacks, most notably when it comes to training the next generation of lawyers.
“One way you get good legal instincts for logical arguments is by getting the reps in—trying things, and doing them over and over,” says Lemley. He worries that wider adoption of AI means young lawyers may not be gaining some of the analytic skills that have traditionally been acquired through extensive reading of case law and statutes.
Lemley also observes that AI is increasingly taking on tasks like writing briefs and crafting arguments, which many attorneys view as the fun part of the job, and which typically fall to more senior attorneys.
All of this raises the question of not just how lawyers will spend their time in the future, but also how they will charge for their services. For years, clients have fought—typically with limited success—to introduce alternative fee arrangements in order to escape paying by the hour for junior associates to go down legal rabbit holes.
In the future, Lemley says, the situation may be reversed as clients—realizing that AI can perform many legal tasks in minutes not hours—ask to be billed for fixed blocks of time, while law firms propose flat fees and other arrangements.
The legal profession has long been adept at guarding its business model, so such changes are likely not on the immediate horizon. But for now, it’s becoming clear that AI is already providing lawyers with something precious: additional time.
According to the Thomson Reuters survey, the widespread adoption of AI will likely free up four hours a week for the typical lawyer, or 200 hours a year—hours that could be used to expand their client base, develop additional skills or, of course, stack billable hours.
A rule of law for AI lawyers
Pablo Arredondo, who created the popular CoCounsel AI tool and is now a vice president at Thomson Reuters, frequently runs seminars for judges about the intersection of law and artificial intelligence.
In the course of his work, he often reflects on a nearly century-old phrase that appears in the very first section of the Federal Rules of Civil Procedure—namely, that judges should encourage the “just, speedy, and inexpensive” resolution of every action.
“Those three words are not how anyone would describe U.S. litigation,” Arredondo says dryly.
This could change if courts adopt AI tools in a widespread and effective fashion. And, indeed, such adoption is already beginning, including in Massachusetts where the court system is adopting automated tools to help tenants facing eviction navigate complex legal forms.
“To the extent this technology can be used for better outcomes, there is a moral imperative to use it,” says Arredondo. Still, he cautions that any deployment of AI by both courts and lawyers must occur with the strictest of oversight.
Arredondo is not alone in that sentiment as the legal profession, like so many other industries, tries to balance the efficiency gains offered by AI with safety. In 2023, reflecting on how the technology is poised to disrupt the work of judges, none other than Chief Justice John Roberts wrote, “Any use of AI requires caution and humility.”