The essay was on The Crucible by Arthur Miller — an allegory to the Salem Witch Trials and the Red Scare. It’s about a community destroying people based on unreliable testimony and refusing to back down. The assignment could hardly have been more on the nose.

In October, a sophomore submitted an essay on the text to his English teacher at Palo Alto High School, Sarah Bartlett. By December, he had been accused of using mostly AI to compose it, and was required to do an in-class rewrite — which got him a D.

His family then submitted drafts, timestamps, and direct access to his Google Doc revision history — culminating in a 1,162-page evidentiary packet sent to the school in January. By March, the family made an offer to the school: give the kid a B, and everyone goes home. 

Palo Alto Unified School District said no. Now the district faces a federal lawsuit, which alleges that Takashi Kato’s son was falsely accused and improperly punished without parental notification. It has become a familiar American story (opens in new tab): a student is flagged by an AI-detection algorithm, a school that won’t back down, and a family left to prove a negative.

The Kato case is not an isolated grievance from an anxious Palo Alto family. It is a stress test of a system that schools across the country have quietly adopted with almost no guardrails: AI-detection software that its own maker acknowledges is fallible, deployed by individual teachers with no standardized threshold for action, no required review process, and no reliable way for a wrongly accused student to clear their name.

Bartlett allegedly flagged Kato’s essay after (opens in new tab)Turnitin (opens in new tab), a software tool used to detect text written by generative AI, such as large-language models, chatbots, word spinners, and bypasser tools, reported that 76% of it had likely been written using AI. Without notifying his parents first, as school policy outlines (opens in new tab), the suit alleges that the ordeal brought Kato’s semester grade from low A or high B to a C for the semester.

The complaint, filed May 5 in the Northern District of California, also alleges that assistant principal Jerry Berkson took Kato’s handwritten rewrite and final exam, had a school secretary type them up, and ran them through Turnitin without notifying the family or obtaining consent. The lawsuit describes the conduct as evidence of “malicious targeting, confirmation bias, and abnormal obsession attempting to justify use of Turnitin.”

The complaint alleges that at least one other Asian student in Bartlett’s class was subjected to the same treatment — flagged by Turnitin, forced to rewrite in class, and handed a D that gutted a previously strong grade. The complaint also alleges a gender disparity: that male students in Bartlett’s class were four to five times more likely than female students to be subjected to the Turnitin assessment and punitive grade replacement.

Taken together, the complaint frames what happened to Kato not as a single teacher’s mistake but as a pattern — one that disproportionately swept up Asian and male students, stripped them of grades they had earned, and was never corrected despite the family’s monthslong effort to force a review. It is on the basis of that pattern that the lawsuit brings the claims of Title IX sex discrimination, and Title VI national-origin discrimination.

The family is asking the court to vacate the rewrite grade, restore Kato’s original semester result, and order the district to expunge any reference to academic dishonesty from every category of record. They are also seeking compensatory damages and attorneys’ fees, and asking the court to bar PAUSD from treating AI detection scores as dispositive evidence without educator review and a meaningful opportunity for the student to respond.

This is, on one level, a lawsuit over a high school essay grade — filed by a family in one of the most academically pressurized ZIP codes in the country, where college admissions results are tracked like box scores and a semester GPA dip can feel like a five-alarm emergency. But the underlying legal and civil-rights questions are neither trivial nor unique to Palo Alto.

At the center of the case is a tool that PAUSD has embraced without clear guardrails for how it should be used. The district’s (opens in new tab)public position on AI (opens in new tab) is that it “embraces the opportunities generative AI offers to enhance teaching and learning” and encourages “open dialogue between teachers and students about how generative AI tools may or may not be used in specific courses.”

The school’s academic integrity policy lists using AI to complete essays as a form of plagiarism, on a par with submitting work written by someone else. But the district has no specific published policy governing how AI-detection tools like Turnitin should be deployed, what score thresholds should trigger disciplinary action, or what process must follow a flag — leaving those decisions, apparently, to individual teachers.

The Palo Alto case is not an isolated one. Leigh Burrell, a sophomore at the University of Houston, received a zero on an assignment (opens in new tab) worth 15% of her final grade after her professor suspected she had used AI — despite Google Docs history showing she had drafted and revised the work over two days. Students at University of Buffalo started a petition after Kelsey Auman, a Master’s student, had her work flagged (opens in new tab) by Turnitin at the end of the semester and was threatened with not being able to graduate.

At the University of Minnesota, a third-year PhD student named Haishan Yang claims he was expelled (opens in new tab) after faculty compared his exam answers to ChatGPT output, costing him his legal right to remain in the United States.

Turnitin works by dividing a submitted document into segments and running each through a classifier trained on large datasets of both human-written and AI-generated text. It then assigns a percentage score representing how much of the document it believes was likely written by an AI.

Turnitin acknowledges a variance of plus or minus 15 percentage points in its scores — meaning the 76% score that triggered Kato’s case could legitimately reflect anywhere from 61% to 91% AI content. The company (opens in new tab)claims a false-positive rate (opens in new tab) of under 1%, but independent research has been less reassuring.

A 2023 study (opens in new tab) published in the International Journal for Educational Integrity tested 14 popular AI detectors and found that even the best-performing tool — Turnitin — struggled significantly with paraphrased AI content, with over 50% of manually edited AI text going entirely undetected across the tools tested.

Stanford University research (opens in new tab) also indicates that neurodivergent students and students for whom English is a second language are flagged at significantly higher rates than native English speakers, because their reliance on repeated phrases and consistent terminology mimics patterns the algorithm associates with AI output.

Turnitin itself is unambiguous about the limits of its own tool. (opens in new tab)On its website (opens in new tab), the company states: “Our AI writing detection model may not always be accurate — it may misidentify human-written, AI-generated, and AI-paraphrased text — so it should not be used as the sole basis for adverse actions against a student. It takes further scrutiny and human judgment in conjunction with an organization’s application of its specific academic policies to determine whether academic misconduct has occurred.”

The teacher’s justification for the punitive rewrite rested on two things: the Turnitin score, and what she claimed was Kato’s admission to using Grammarly for “synonym assistance.” The Kato family denies the admission ever happened. But even if it had — Grammarly is not an AI writing tool. It is a grammar and editing assistant that millions of students use routinely, often without thinking of it as “AI” at all.

There is also a compounding and largely unreported problem: according to Turnitin, using Grammarly can trigger (opens in new tab) higher AI detection scores. Turnitin doesn’t analyze a student’s process — it analyzes the final text. A 2025 study (opens in new tab) in the International Journal of Educational Technology in Higher Education found that even a known human-written abstract edited with Grammarly returned a 16% AI score on Turnitin.

Grammarly itself acknowledges (opens in new tab) that its more advanced rewriting features — including its paraphrasing and proofreading agents — are powered by large language models and “should still lead to some percentage of AI-generated text being triggered in AI detection.” Even Turnitin’s own educator forum community (opens in new tab)has flagged the problem (opens in new tab), with teachers noting that student work composed using Grammarly can return AI scores of 100%.

The pressure on educators to respond is real — and for some, exhausting enough to push them out of the profession entirely (opens in new tab). In response, many teachers and professors have returned to in-class essays (opens in new tab), where they can watch students write in real time by hand. The share of U.S. teens (opens in new tab) using ChatGPT for schoolwork doubled from 13% in 2023 to 26% in 2024.

By late 2025, that number had climbed to roughly 54%, while 59% of teens said AI cheating had become a regular occurrence at their school. A (opens in new tab)2024 Wiley survey (opens in new tab) found that nearly all college instructors — 96% — believed at least some of their students had cheated over the previous year, up from 72% in 2021.

The lawsuit alleges the district’s final answer, delivered by outside counsel from the firm Dannis Woliver Kelley on April 23, was that it was “unable to offer a manner in which to resolve the grade change matter.”

As the complaint puts it, “revision of the final grade back to the earned ‘B’ grade and elimination of any reference or implication of academic dishonesty from the student’s school record is required to avoid further harm to the student.”

Palo Alto Unified declined to comment, citing its policy against commenting on pending litigation.