Donald J. Trump’s defense lawyers will call his son and fellow defendant Eric Trump back to the witness stand this week, along with more expert witnesses to testify on the former president’s behalf.

Mr. Trump, who already testified during his civil fraud trial last month, is scheduled to testify again on Dec. 11 before his lawyers rest their case.

The trial, which started in October, stems from a lawsuit brought by the New York attorney general, Letitia James. She has accused Mr. Trump and other defendants, including his companies and his sons Donald Jr. and Eric of inflating the value of assets to obtain favorable loans and insurance deals.

Today marks the 39th day of the civil fraud trial and kicks off the fourth week of the defendants’ case.

The judge, Arthur F. Engoron, ruled even before the trial began that Mr. Trump and the other defendants were liable for fraud. After the trial he will decide what punishments they should face. Ms. James has asked that the former president pay $250 million and that he and his sons be permanently barred from running a business in New York.

Mr. Trump has denied all wrongdoing. His lawyers have argued that the assets had no objective value and that differing valuations are common in real estate.

Here is what happened last week:

Current and former bankers from Deutsche Bank testified on behalf of Mr. Trump.

David Williams, a banker with the institution’s private wealth management group, said that financial statements like Mr. Trump’s relied on estimates. As a result, he said, the bank conducted its own due diligence and adjusted the numbers downward.

At one point, Mr. Williams testified that Mr. Trump’s net worth had been adjusted to $2.6 billion from the $4.9 billion he originally reported, and that such a large change was not unusual in his line of work.

The court also heard from Rosemary Vrablic, a former Deutsche Bank employee who served as an intermediary between the bank and the Trump family and who oversaw hundreds of millions of dollars of loans to Mr. Trump.

Jesus Suarez, a lawyer for Mr. Trump, asked Ms. Vrablic about old emails showing the bank’s excitement in having the Trump family as clients. Early in the relationship, Ms. Vrablic told her colleagues in a 2011 email that she expected the Trump family to introduce the bank to “the wealthiest people on the planet.”

Years later, Ms. Vrablic told the former president’s daughter Ivanka Trump that the Trump family was among the top 10 clients in her division in terms of revenue generation, and that her boss was thrilled with how their business had grown.

Mr. Trump’s lawyers then called Robert Unell, an expert witness in commercial real estate financing, to support the testimony of the bankers.

Mr. Unell praised Mr. Trump’s financial statements, saying they were of better quality than those typically received in real estate transactions. But he said such statements were only meant to serve as a “road map” for banks to conduct their own analysis.

Mr. Unell also said that Deutsche Bank would have been excited about having Mr. Trump as a client, as he would have been able to make introductions to other high-net-worth clients and help the bank’s private wealth business expand.

In response to the testimony, Justice Engoron said wryly, “If there is one thing we’ve learned over the last eight weeks, it is that banks like billionaires.”

During the trial’s first week, Mr. Trump shared a post on social media showing Justice Engoron’s law clerk, Allison Greenfield, standing next to Chuck Schumer, the Democratic Senate majority leader. Mr. Trump falsely referred to her as “Schumer’s girlfriend” in the post and accused her of “running this case against me.”

In response, Justice Engoron issued a gag order prohibiting Mr. Trump from commenting on the judge’s staff. He later issued a similar gag order against Mr. Trump’s lawyers after they questioned Ms. Greenfield’s prominence in the case and accused her of partisan bias because she is a Democrat.

Over the past two months, Mr. Trump has violated the gag order twice, resulting in $15,000 in fines.

His lawyers appealed the orders, and another judge, David Friedman, temporarily halted them. Mr. Trump then criticized Ms. Greenfield on social media, calling her “disturbed and angry.”

The gag orders were reinstated last week after a review by an appeals court panel. Justice Engoron addressed the reinstatement in court on Thursday, saying he intended to enforce the orders “rigorously and vigorously.”

One of Mr. Trump’s lawyers, Christopher M. Kise, released a statement saying, “In a country where the First Amendment is sacrosanct, President Trump may not even comment on why he thinks he cannot get a fair trial.”

After Mr. Trump’s lawyers rest their case next week, the attorney general’s lawyers are expected to call several witnesses to offer rebuttal testimony.

The trial will then break until January. Both sides will submit written briefs and then return to the courtroom on Jan. 11 for closing arguments.

A few weeks later, Justice Engoron is expected to release his decision.