Early this month, Mr. Vance enlisted a prominent figure in New York legal circles, Mark F. Pomerantz, to help with the investigation. Mr. Pomerantz, a former senior federal prosecutor with significant experience both investigating and defending complex white-collar and organized crime cases, will handle interactions with key witnesses, among other tasks.
For additional help, Mr. Vance’s office has hired FTI, a large consulting company that can analyze some of the industries in which Mr. Trump’s companies operate, including commercial real estate, as well as tax issues, people with knowledge of the matter said.
The firm will also load the trove of records into a data analysis and document management system that it can use to explore the materials and seek patterns in support of the investigation, the people said.
The action by the Supreme Court justices, who without noted dissent denied Mr. Trump an emergency stay so the court could fully review issues in the case for a second time, will not put Mr. Trump’s tax returns in the hands of Congress or make them automatically public. Grand jury secrecy laws will keep the records private unless Mr. Vance’s office files charges and enters the documents into evidence at a trial.
The public has already learned a great deal about Mr. Trump’s taxes through other means. Nearly all of his tax information from the last few decades was obtained by The New York Times, which published a series of investigative stories last year showing that he paid virtually no income tax for many years and that he is currently under an audit in which an adverse ruling could cost him more than $100 million. He and his companies file separate tax returns and employ complicated and sometimes aggressive tax strategies, The Times found.
But the Supreme Court’s action set in motion a series of events that could lead to the extraordinary possibility of a criminal trial for former president. At a minimum, the ruling wrests from Mr. Trump control of his most closely held financial records and the power to decide when, if ever, they would be made available for public inspection.
Mr. Trump and his lawyers have long fought to keep the records secret. After promising during the 2016 campaign to release his tax returns, as every presidential candidate has done for at least 40 years, he refused to do so, providing a persistent line of criticism for Democrats and other adversaries.