It has long been President Trump’s impulse to tar his enemies with the same accusations they have lobbed at him.

And his Justice Department’s criminal case against the New York attorney general, Letitia James, carries echoes of the civil fraud case she brought against him — albeit at a scale so small that most federal prosecutors would never deign to pursue it.

The indictment, less than a month after Mr. Trump publicly exhorted the Justice Department to pursue Ms. James, accuses her of violating a mortgage agreement on a Virginia house she purchased in 2020 by using it as a rental property.

The case is a fresh reminder of how the president has taken the Justice Department in hand and directed its prosecutorial powers toward his adversaries. Ms. James is the second of his enemies to be indicted in the past two weeks after he insisted that a case be pursued. Just five days before the charges against Ms. James were handed up, he called her “corrupt” and “scum” on his social media platform and said she should be removed from the New York attorney general’s office.

The indictment charges Ms. James with one count apiece of bank fraud and false statements to financial institutions and says that by misrepresenting her intentions for the house, she received favorable terms that would have allowed her to save $18,933 over the life of the loan.

A federal case concerning such a small sum would be highly unusual even absent the politics shadowing the charges against Ms. James, and the indictment’s factual claims are likely to be disputed. A person familiar with Ms. James’s housing arrangements said that the property had never been used as a rental and was occupied by Ms. James’s family members. There was no rental agreement and Ms. James has continued to pay the mortgage, said the person, who was not authorized to speak publicly.

Ms. James is set to appear in a Virginia court on Oct. 24. It is likely that she will seek to persuade a judge to dismiss the charges before a trial, arguing that they stem from a vindictive and selective prosecution. But the stakes are high — if convicted, Ms. James faces the possibility decades in prison.

In a statement, a lawyer for Ms. James, Abbe D. Lowell, said that Ms. James “flatly and forcefully denies these charges.”

“We are deeply concerned that this case is driven by President Trump’s desire for revenge,” he wrote. “When a president can publicly direct charges to be filed against someone — when it was reported that career attorneys concluded none were warranted — it marks a serious attack on the rule of law.”

The immediate circumstances surrounding the indictment of Ms. James on Thursday were unusual in several respects.

The case, which was brought in the Eastern District of Virginia, is expected to proceed in Norfolk, but was presented before a grand jury in Alexandria, just outside Washington, D.C.

Like the Trump Justice Department’s case against the former F.B.I. director James B. Comey, another nemesis of the president, it was brought by Lindsey Halligan, a former personal lawyer to Mr. Trump with no prior experience as a prosecutor. The president pushed out Ms. Halligan’s predecessor, Erik S. Siebert, for expressing skepticism about cases against Ms. James and Mr. Comey.

Also like the Comey case, Ms. Halligan was the only prosecutor whose name appeared on the indictment. In most cases, the rank and file prosecutors who handled the investigation sign the court filings.

In recent weeks, career prosecutors in the Norfolk division of the U.S. attorney’s office had looked at the evidence against Ms. James and believed it did not merit criminal charges, according to people familiar with the matter who spoke on the condition of anonymity to describe an ongoing case. A senior prosecutor in that division relayed that determination to her superiors, according to the people.

Despite that, Ms. Halligan chose to proceed.

As Ms. James knows firsthand, even civil fraud cases, which have a lower burden of proof than criminal cases, can be difficult to win. Though she initially triumphed in the civil fraud trial of Mr. Trump, which was overseen by a New York judge, a state appellate court recently threw out the half-billion dollar penalty. The appeals panel reached a shaky agreement to uphold the finding that Mr. Trump was liable for fraud, but only so that the entire case could be evaluated by the state’s highest court.

Still, Mr. Trump was humiliated by Ms. James’s lawsuit and the subsequent trial, which took aim at one of his most prized assets: his public image as a self-made billionaire. Ms. James accused him of a yearslong pattern of exaggerating his net worth on annual financial statements in order to receive favorable loan terms from banks and insurers.

Her case was years in the making. When Ms. James ran to be New York attorney general in 2018, she pledged to investigate Mr. Trump and his family business. One of her refrains was “No one is above the law.”

She was elected and, the following year, opened an inquiry into Mr. Trump predicated on congressional testimony from his former fixer, Michael D. Cohen.

In 2022, Ms. James sued Mr. Trump, accusing him of inflating his net worth by billions of dollars, and the following year, she took him to trial, where the value of individual properties in his empire — many of them worth multiples of what Ms. James is accused of retaining in ill-gotten gains — was closely scrutinized.

Both Ms. James and Mr. Trump attended the trial regularly, sitting just feet from one another.

Mr. Trump pledged revenge before the case even reached a conclusion. In January 2024, he took over the microphone during the fraud trial’s closing arguments and fumed at Ms. James directly, saying that her case was in fact “a fraud on me.” Ms. James, he said, “should pay me for what we had to go through.”

The following year, in April, Bill Pulte, the head of the Federal Housing Finance Agency, initiated the case against Ms. James. He sent a criminal referral to the Justice Department suggesting that the New York attorney general “appeared to have falsified records” and indicated that she might have committed mortgage fraud.

Mr. Pulte has since targeted other enemies of Mr. Trump with similar allegations. But the accusations against Ms. James are the first to make their way into an indictment.

Mr. Pulte celebrated on Thursday evening, promoting a social media post that said, “Bill Pulte doesn’t play. They all thought their mortgage scams were safe. They were wrong. This is just the beginning.”

Ms. Halligan, the U.S. attorney who secured the indictment, issued her own statement. It began with a familiar phrase: “No one is above the law.”