Federal agents armed with a search warrant have seized the phone of John Eastman, a lawyer who advised former President Donald J. Trump on key elements of the effort to overturn the results of the 2020 election, according to a court filing by Mr. Eastman on Monday.
The seizure of Mr. Eastman’s phone is the latest evidence that the Justice Department is intensifying its sprawling criminal investigation into the various strands of Mr. Trump’s efforts to remain in power after he was defeated for re-election.
In the past week alone, the department has delivered grand jury subpoenas to a variety of figures with roles in backing Mr. Trump’s efforts and it carried out at least one other search of a key figure.
The filing by Mr. Eastman, a motion to recover property from the government, said that F.B.I. agents in New Mexico, acting on behalf of the Justice Department’s Office of the Inspector General, stopped Mr. Eastman as he was leaving a restaurant last Wednesday and seized his iPhone.
A copy of the warrant included as an exhibit in Mr. Eastman’s filing said that the phone would be taken to either the Justice Department or the inspector general’s forensic lab in Northern Virginia.
According to the filing, the seizure of Mr. Eastman’s phone came on the same day that federal agents raided the home and seized the electronic devices of Jeffrey Clark, a former Justice Department official who was central to Mr. Trump’s attempts to coerce the department’s leaders into backing his false claims of fraud in the election.
The inspector general’s office, which has jurisdiction over investigations of Justice Department employees, also issued the warrant in the search of Mr. Clark’s home, a person familiar with the investigation said. The warrant indicated that prosecutors are investigating Mr. Clark for charges that include conspiracy to obstruct the certification of the presidential election, the person familiar with the investigation said.
A spokesman for the U.S. attorney’s office in Washington, which is overseeing the inquiry, declined to comment on Mr. Eastman’s court filing.
With Mr. Eastman and Mr. Clark, the department is gathering information about two lawyers who were in close contact with Mr. Trump in the critical weeks before the Jan. 6, 2021, attack on the Capitol by a pro-Trump mob.
The advice they were giving Mr. Trump involved separate but apparently intersecting proposals to provide him with a means of averting his defeat, with Mr. Clark focused on using the power of the Justice Department on Mr. Trump’s behalf and Mr. Eastman focused on disrupting the congressional certification of the election’s outcome.
The search warrant executed on Mr. Eastman by the inspector general’s office may have been issued because of his connections to Mr. Clark, which were briefly touched on at a hearing by the House select committee on Jan. 6 last week, a day after the raids on the two men.
At the hearing, Representative Liz Cheney, Republican of Wyoming and the panel’s vice chairwoman, said that Ken Klukowski, a Justice Department lawyer who was in contact with Mr. Eastman, also helped Mr. Clark draft a letter to Gov. Brian Kemp of Georgia stating falsely that the Justice Department had identified “significant concerns” about the “outcome of the election” in Georgia and several other states.
The letter further recommended that Mr. Kemp call a special session of the state legislature to create “a separate slate of electors supporting Donald J. Trump.”
Mr. Klukowski, who briefly served under Mr. Clark at the Justice Department and had earlier worked at the White House budget office, also “worked with John Eastman,” Ms. Cheney said during the hearing. She went on to describe Mr. Eastman as “one of the primary architects of President Trump’s scheme to overturn the election.”
The inspector general’s office has the authority to look into any public corruption crimes committed by Justice Department personnel, said Michael R. Bromwich, a former department inspector general during the Clinton administration.
“Those investigations can lead to people and places outside the Justice Department,” Mr. Bromwich said. “There must be a connection between Eastman and someone who worked at the department.”
Key Revelations From the Jan. 6 Hearings
A former law professor in California, Mr. Eastman helped develop and promote a brazen plan to justify having Vice President Mike Pence single-handedly block or delay certification of the Electoral College results showing Joseph R. Biden Jr.’s victory in the 2020 election. In a series of meetings and phone calls, Mr. Trump and Mr. Eastman pressured Mr. Pence to put the plan into action when Mr. Pence presided over a joint session of Congress on Jan. 6, 2021.
Mr. Pence’s refusal to go along helped fuel the violence that overwhelmed the Capitol that day and became a bloody symbol of Mr. Trump’s efforts to subvert the outcome of the election. Earlier this a year, a federal judge in California considering a civil suit concerning the release of Mr. Eastman’s emails to the House select committee concluded that Mr. Eastman and Mr. Trump most likely committed two felonies — obstruction of a proceeding before Congress and a conspiracy to defraud the United States — for their joint role in the pressure campaign against Mr. Pence.
Mr. Eastman was also instrumental in advising Mr. Trump to create purported slates of electors backing Mr. Trump in key swing states won by Mr. Biden. These false pro-Trump electors were intended to give Mr. Pence a quasi-legal rationale for delaying or blocking the Electoral College certification on Jan. 6, or even trying to throw the election to the House of Representatives.
Last week, a federal grand jury in Washington issued subpoenas to several people who prosecutors believe may have information about the so-called fake elector plan. Among those who received subpoenas were top Republicans in key swing states who served as purported pro-Trump electors, including Kelli Ward, the chairwoman of the Arizona Republican Party, and David Shafer, the chairman of the Georgia Republican Party.
The subpoenas, some of which have been obtained by The New York Times, show that prosecutors are seeking information about lawyers like Mr. Eastman who were close to Mr. Trump during the chaotic postelection period. The subpoenas also seek information on other lawyers like Rudolph W. Giuliani, who oversaw Mr. Trump’s election challenges in general, and Kenneth Chesebro, who wrote legal memos laying out the viability of the fake elector plan.
In Mr. Eastman’s court papers, filed in Federal District Court in New Mexico, he says that the search warrant did not mention what underlying crime prosecutors were looking into by seizing his phone.
On Monday night, Mr. Eastman appeared on Tucker Carlson’s Fox News show and discussed the seizure of his phone, repeating his complaint that the warrant never specified what violation of the law prosecutors were investigating.
“There was no indication of any crime this is connected to,” he said.