The Los Angeles schools superintendent resigned on Sunday, months after the F.B.I. raided his home and office in February in connection with a criminal inquiry into the district’s dealings with an A.I. start-up.
The superintendent, Alberto Carvalho, was a well-known education leader who was hired in 2021 to lead the Los Angeles Unified School District, the nation’s second largest, serving about 400,000 students. He had been on paid leave since Feb. 27, when the Board of Education suggested he step back to quell mounting turmoil over the investigation.
It was not immediately clear who would replace him. A veteran Los Angeles Unified administrator, Andres Chait, has been the acting superintendent since Mr. Carvalho’s paid leave began.
Mr. Carvalho’s resignation, which was effective immediately, was conveyed in a letter sent Sunday to the district and members of the school board.
“Over the past four years, together, we have made historic progress — gains that belong to our students, our educators, staff and our communities,” Mr. Carvalho said.
“Placing students first has always guided my work,” Mr. Carvalho wrote. “Because I believe our schools must remain focused on students and learning without distraction, I am resigning.”
His resignation was first reported by The Los Angeles Times.
The school board said on Monday that it “remains steadfast in its commitment to ensuring stability, continuity, and continued progress through strong leadership” and that Mr. Chait would remain until a “permanent decision” was made.
The school board plans to meet on Wednesday to discuss its next steps.
Mr. Carvalho, a 61-year-old native of Portugal, has long been a player at the top levels of American public education. He came to Los Angeles after a 14-year tenure as superintendent in Miami, during which he boosted student test scores and built a reputation for tech innovation and nurturing the education of poor students.
In March, his lawyers issued a statement saying that he had committed no wrongdoing, and that “no evidence has been presented by prosecutors supporting any allegation that Mr. Carvalho violated federal law.”
The federal inquiry into Mr. Carvalho stems from a district contract with AllHere, a Boston tech company that collapsed amid fraud charges.
A longtime associate and friend of Mr. Carvalho’s, Debra Kerr, was a consultant for the company. Ms. Kerr, who lived in Florida, met Mr. Carvalho while he was the superintendent of the Miami-Dade County Public Schools.
AllHere collapsed financially in July 2024. Four months later, its chief executive, Joanna Smith-Griffin, was indicted on charges that she had defrauded investors.
The F.B.I. searched Ms. Kerr’s home in Broward County, Fla., in late February, on the same day that they searched Mr. Carvalho’s Los Angeles office and home.
School district officials have indicated that the government’s focus is financial and aimed at Mr. Carvalho and Ms. Kerr, rather than at the Los Angeles school system.
They said that after AllHere collapsed, the school board commissioned an investigation by outside counsel to look into Mr. Carvalho’s role in the contract and found no criminal wrongdoing on his part.
The district, which has started its own internal review of contracts approved during Mr. Carvalho’s tenure, has been cooperating with the authorities. District records indicate that after Mr. Carvalho’s arrival, Los Angeles Unified contracted with at least two other companies that Ms. Kerr promoted.
Mr. Carvalho had been highly regarded in education circles, and some defended him after the investigation, suggesting that the Trump administration, which has clashed with California’s Democratic leaders repeatedly, may have targeted him.
Mr. Carvalho moved to New York after high school. He has said he became undocumented for a time after overstaying his visitor visa, working at restaurants, farms and construction sites. He even fell into homelessness. After about two years, he has said, he secured documentation, eventually going on to become a physics teacher and a U.S. citizen.
Mr. Carvalho has been outspoken about the administration’s aggressive crackdown on immigration, and has publicly defended the rights of immigrant students. He also has been open about his own experience as a transplant to the United States.
His career has also had moments of scandal.
In 2008, leaked emails suggested that he had a romantic relationship with a reporter covering Miami schools. According to The Miami Herald, Mr. Carvalho denied having an affair with the reporter, but said that the emails he wrote were inappropriate.
In 2018, he accepted what some consider to be the most prestigious position in public education, leader of the New York City school system, but then abruptly backed out of the job on live television.
In Los Angeles, he clashed repeatedly with the superintendent he succeeded, Austin Beutner, and dismantled popular academic programs that Mr. Beutner had championed. Last year, Mr. Beutner and a group of Los Angeles Unified students filed a lawsuit accusing the district and Mr. Carvalho of misusing more than $76 million in art and music education funds.
Livia Albeck-Ripka contributed reporting.