Aug. 21, 2018

Michael D. Cohen says he arranged hush-money payments for the president, and the investigation begins.

Mr. Cohen, previously a personal lawyer and fixer for Mr. Trump, pleaded guilty to federal crimes and told a court that Mr. Trump had directed him to arrange payments to two women. The payments were made during the 2016 campaign to keep the women from speaking publicly about affairs they said they had conducted with Mr. Trump.

Soon after Mr. Cohen’s admission, the Manhattan district attorney’s office opened an investigation to examine if the payments broke New York State laws. The office soon paused the inquiry at the request of federal prosecutors, who were looking into the same conduct.

August 2019

The district attorney’s office subpoenas the Trump Organization.

After federal prosecutors said that they had “effectively concluded” their investigation, Cyrus R. Vance Jr., the Manhattan district attorney at the time, revived his own inquiry. Late in the month, prosecutors in his office issued a subpoena to the Trump Organization and another subpoena to Mr. Trump’s accounting firm, demanding eight years of Mr. Trump’s personal and corporate tax returns.

Sept. 19, 2019

Mr. Trump’s lawyers sue to protect his tax returns.

The lawsuit, filed in U.S. District Court in Manhattan, argued that a sitting president cannot be criminally investigated. It led to a lengthy delay.

July 9, 2020

Mr. Vance wins his first key victory at the U.S. Supreme Court.

After appellate judges ruled against Mr. Trump, the lawsuit found its way to the Supreme Court, where the justices ruled that the presidency did not shield Mr. Trump from criminal inquiries and that he had no absolute right to block the release of his tax returns.

The ruling left Mr. Trump with the opportunity to raise different objections to Mr. Vance’s subpoena.

AUTUMN 2020

The investigation intensifies.

Prosecutors interviewed employees of the main bank and insurance company that serve Mr. Trump and issued several new subpoenas.

The district attorney’s office also signaled in another court filing that it had grounds to investigate the president for tax fraud.

Feb. 22, 2021

The Supreme Court denies Mr. Trump’s final bid to block the release of his returns.

The brief unsigned order was a decisive defeat for Mr. Trump and a turning point in Mr. Vance’s investigation.

Just hours later, eight years of financial records were handed over to Mr. Vance’s office.

March 1, 2021

The investigation’s focus turns to a top executive.

In the spring, Mr. Vance’s prosecutors set their sights on Allen H. Weisselberg, the Trump Organization’s long-serving chief financial officer, whom they hoped to pressure into cooperating with their investigation.

The prosecutors were particularly interested in whether the Trump Organization handed out valuable benefits to Mr. Weisselberg as a form of untaxed compensation.

July 1, 2021

The Trump Organization is charged with running a 15-year tax scheme.

When Mr. Weisselberg refused to testify against his boss, prosecutors announced charges against him and Mr. Trump’s company, saying that the company helped its executives evade taxes by compensating them with benefits such as free cars and apartments that were hidden from the authorities.

JAN. 1, 2022

A new Manhattan district attorney takes office.

Mr. Vance left office, and his successor, Alvin L. Bragg, took over the case. Both are Democrats.

Mr. Bragg, a former federal prosecutor, retained two of the investigation’s leaders, Mark F. Pomerantz, an experienced former federal prosecutor and white-collar defense lawyer, and Carey Dunne, Mr. Vance’s general counsel.

Feb. 23, 2022

Two prosecutors resign, leaving the investigation’s future in doubt.

After Mr. Bragg expressed reservations about the case, Mr. Pomerantz and Mr. Dunne suspended the presentation of evidence about Mr. Trump to a grand jury. A month later, they resigned, prompting a public uproar over Mr. Bragg’s decision not to proceed with an indictment.

In his resignation letter, which was later obtained by The New York Times, Mr. Pomerantz said that Mr. Trump had been guilty of numerous felonies.

Aug. 18, 2022

Mr. Bragg’s investigation continues.

After staying mostly silent through weeks of criticism, the district attorney publicly discussed his office’s investigation of Mr. Trump for the first time. His fundamental message: The inquiry would continue.

Aug. 18, 2022

Allen Weisselberg pleads guilty and agrees to testify against the Trump Organization.

Though the chief financial officer declined to turn on Mr. Trump himself, he agreed to testify at the October trial against the company that he had served for nearly half a century.

Late Summer, 2022

The prosecutors turn back to hush money.

After several months, Mr. Bragg’s prosecutors returned to the long-running investigation’s original focus: a hush-money payment to Stormy Daniels, a pornographic film actress who said she had a sexual relationship with Mr. Trump.

Dec. 6, 2022

The Trump Organization is convicted, securing a significant victory for the district attorney.

Mr. Bragg’s prosecutors won a conviction of Mr. Trump’s family business, convincing a jury that the company was guilty of tax fraud and other crimes.

January 2023

The district attorney impanels a new grand jury.

The grand jury met throughout the next three months and heard testimony about the hush-money payment from at least nine witnesses.

Midwinter 2023

Prosecutors signal that an indictment is likely, offering Mr. Trump a chance to testify before the grand jury.

Such offers almost always indicate an indictment is close; it would be unusual to notify a potential defendant without ultimately seeking charges against him.

March 18, 2023

Mr. Trump predicts his arrest and calls for protests.

Without any direct knowledge, the former president posted on his Truth Social account that he would be arrested three days later and sought to rally supporters to his side. His prediction was soon walked back, and he was not arrested at that time.

March 30, 2023

Mr. Trump is indicted by a grand jury.

The grand jury indicted Mr. Trump on 34 felony charges — the first against any American president, current or former.