A lawyer who helped design the plan to appoint a slate of “alternate” Republican presidential electors in Georgia and other swing states won by Joe Biden in 2020 cited attorney-client privilege and pleaded the 5th Amendment during his testimony Wednesday before a Fulton County special grand jury.

Attorneys for John Eastman said they advised their client to cite those protections, including the right to remain silent, “where appropriate” as he answered questions from Fulton prosecutors and the 23-person grand jury this morning.

“Out of respect for grand jury secrecy we will not disclose the substance of the questions or testimony,” attorneys Charles Burnham and Harvey Silverglate wrote in a joint statement.

Silverglate, a Massachusetts-based defense attorney and civil liberties advocate, estimated that Eastman was in the grand jury room for no longer than two hours.

Eastman is one of several lawyers for the Trump campaign, including Rudy Giuliani, who have been compelled to testify before the grand jury, which is probing whether former President Donald Trump or his allies broke any state laws as they sought to overturn Biden’s win in Georgia.

Eastman was involved in at least two matters that are of interest to the grand jury.

He was allegedly a key architect of the plan to press Vice President Mike Pence to refuse to count the official Democratic electors in Georgia and a half-dozen other contested swing states on Jan. 6, 2021. Instead, Pence would recognize a set of Trump electors.

To that end, 16 Georgia Republicans signed paperwork in the state Capitol in December 2020 claiming to be the state’s duly elected presidential electors.

Pence rejected the idea, but a federal judge in March argued that “it is more likely than not that President Trump and Dr. Eastman dishonestly conspired to obstruct the Joint Session of Congress on January 6, 2021.”

Eastman also testified at a Dec. 2020 statehouse hearing of interest to the grand jury. During his remarks, Eastman argued that there was “more than enough” evidence of fraud and improper conduct to warrant Georgia lawmakers picking an alternative slate of presidential electors.

“I don’t think it’s just your authority to do that,” Eastman said, “but, quite frankly, I think you have a duty to do that to protect the integrity of the election here in Georgia.”

In its summons seeking Eastman’s testimony, the grand jury said there is evidence that Eastman’s appearance at the hearing and work on the phony electors scheme was “part of a multi-state, coordinated plan by the Trump Campaign to influence the results of the November 2020 election in Georgia and elsewhere.”

All 16 of Georgia’s fake electors were sent “target” letters earlier this summer alerting them they could be indicted, along with Giuliani. (The Fulton DA’s office was later barred from investigating one of those electors, state Sen. Burt Jones, due to a political conflict of interest.)

In an email to The Atlanta Journal-Constitution, Silverglate said that based on his knowledge, Eastman “has not been advised that he is a target” of the investigation.

“I do not believe that Mr. Eastman will be named a target at any point because the evidence is clear that he has not committed any crimes,” he said. “I challenge any journalist to suggest what crimes he supposedly committed.”

His comments came shortly after The New York Times quoted him saying that Eastman is “probably” a target, though not in his eyes a legitimate one.

A spokesman for the Fulton DA’s office did not immediately respond to a request for comment.

Burnham and Silverglate in their written statement warned that the District Attorney’s office “has set itself on an unprecedented path of criminalizing controversial or disfavored legal theories, possibly in hopes that the federal government will follow its lead.”

“Criminalization of unpopular legal theories is against every American tradition and would have ended the careers of John Adams, Ruth Ginsburg, Thurgood Marshall and many other now-celebrated American lawyers,” they wrote.

Silverglate said he considered the pursuit of Eastman’s testimony in Fulton “part of a much larger witch-hunt of sorts.”

“In my view, he has engaged in protected political activity as well as speech, and yet he is being pursued as if he were a mass murderer,” he told the AJC. “I would hope that my fellow liberals would agree with me although I suspect that, sadly, many will not.”

On Tuesday, Kenneth Chesebro, a Trump campaign attorney from New York, appeared before the special purpose grand jury, according to court filings.

Fulton prosecutors say Chesebro worked with the leadership of the Georgia Republican Party to coordinate the slate of alternate electors . Prosecutors also say Chesebro worked directly with Giuliani to carry out the plan.

Chesebro’s attorney, prominent white collar defense lawyer Scott Grubman, declined to discuss his client’s testimony. But he was critical of the ongoing probe involving Trump’s legal team.

“Lawyers who take on unpopular clients and provide legal counsel should not find themselves under investigation,” Grubman said. “It’s a slippery and exceedingly dangerous slope.”

Staff writer Bill Rankin contributed to this article.