The first member of the Biden family to testify at the trial could take the stand today, as prosecutors are expected to call Hallie Biden as their next witness.

Hallie Biden, who was married to Hunter Biden's brother Beau Biden until his death from cancer in 2015, was Hunter Biden's romantic partner at the time he purchased the firearm at the center of the case in 2018.

Prosecutors suggested yesterday that she could take the stand after FBI Special Agent Erika Jensen, the trial's first witness, completes her testimony.

Jensen will be back on the stand this morning to continue her cross-examination by Hunter Biden's attorneys.

According to a transcript of Tuesday's proceedings released hours after court concluded, at attorney for Hunter Biden told the judge during a sidebar conversation that he might decide to call Hunter Biden's oldest daughter, Naomi Biden, to testify at trial "if need be."

Attorney Abbe Lowell made the statement during what appeared to be a tense exchange between him, Judge Maryellen Noreika and two government prosecutors, in which Lowell divulged his expectations for witnesses.

When prosecutors suggested Lowell was hiding the ball on how he planned to present certain evidence, Lowell first introduced the idea of calling one of Hunter Biden's daughters as a witness:

MR. HINES: Exactly, we have asked Mr. Lowell and he won't tell us.
MR. LOWELL: That's not what I said.
MR. HINES: He couldn't tell us which witness.
MR. LOWELL: I said I'm making a proffer and the court -- I understand the rules, each one of these will be submitted with a witness, I don't have to tell them in advance which witness it is, but I am making a statement to the Court, there is three or four witnesses, including his uncle and his daughter, if need be.

Lowell later clarified that Naomi Biden, Hunter Biden's daughter with ex-wife Kathleen Buhle, and the president's eldest granddaughter, was on his witness list.

Lowell also left the door open for Hunter Biden to testify "if it gets to that," a gamble that would put his client in the position of facing live cross-examination from federal prosecutors. It came during a discussion about how Lowell planned to demonstrate that Hunter Biden read the ATF Form 4473 "carefully."

THE COURT: Wait. Just so I'm clear, are you going to suggest that he did in fact read these things or just that if he had chosen to and didn't tell them.
MR. LOWELL: Both.
THE COURT: What is your evidence going to be that he did in fact read all of these things carefully?
MR. LOWELL: If it gets to that judge, then it will be Mr. Biden's job to say that.

During a debate at the same bench conference about an argument Lowell intended to make in his opening statement, Judge Maryellen Noreika called the defense attorney for interrupting her.

MR. LOWELL: That's not the argument judge.
THE COURT: That is what it sounds like you're telling me, you're saying he doesn't know what it was.
MR. LOWELL: No.
THE COURT: You keep cutting me off, and you want to make your argument, and I know you want to make your argument, but you need to understand it, so you need to understand where I am.

The judge later told Lowell, "Don't put words in my mouth."

"I know you're just trying to zealously represent your client," she said, "but don't assume my ruling before you give me a chance to make it."

Attorneys for Hunter Biden, in their cross-examination of FBI Special Agent Erika Jensen, attempted to push back on prosecutors' contention that Hunter Biden was abusing drugs at the time he said on a gun-purchase form that he was drug-free.

A key piece of evidence comes from Hunter Biden's 2021 memoir, in which he described his "relapse" just weeks after leaving rehab in August -- just six weeks before purchasing the firearm.

"I stayed clean for two weeks then relapsed," Hunter Biden wrote in his book.

Defense attorney Abbe Lowell, on cross-examination, questioned the assumption that Hunter Biden's relapse implied that he was referring to his drug use -- suggesting instead that he was referring to his alcohol addiction.

"When he was referring to that in his book, was he talking about relapsing to drugs and alcohol, or do you know what he meant?" Lowell asked.

"I can only state what was stated," Jensen said.

"Which is, 'Then I relapsed?'" Lowell asked.

"Just what it says, 'I relapsed,'" Jensen replied.

Jensen also acknowledged that she could not verify that Hunter Biden was continuously using drugs from 2015 to 2019, saying, "My recollection is that there are excerpts where he was principally occupied with smoking crack cocaine. I didn't get the sense that it was the entire history."

"Meaning that there were periods of time that he was not?" Lowell asked.

"I think there -- including the period in August where we have some invoices for rehab, that there were periods where there was not," Jensen said.

It was an important moment for the defense, as Lowell managed to establish that Hunter Biden's use of drugs was not consistent -- cuing up his argument that the president's son was not on drugs at the time of his firearm purchase.

Prosecutors also entered into evidence records related to enormous cash withdrawals Hunter Biden made -- more than $150,000 from September through November of 2018, including a $5,000 withdrawal on the day he purchased the gun. Prosecutors suggested this cash was used to procure drugs; Lowell, on cross-examination, established that Hunter Biden paid $900 in cash for the weapon and accessories.

Court was subsequently recessed for the day, with Lowell's cross-examination of Jensen scheduled to resume Wednesday morning.

Prosecutors suggested that Hallie Biden would be the next witness after Jensen, making it likely that the first Biden family member to testify will take the stand at some point tomorrow.

Testifying for the prosecution, FBI Special Agent Erika Jensen presented evidence involving a 2018 text message exchange between Hunter Biden and Hallie Biden, his brother Beau's widow who was Hunter Biden's romantic partner at the time.

An angry Hunter Biden texted Hallie Biden on the day she discovered his gun.

"Did you take that from me? ... You're being totally irresponsible and unhinged," the text said.

"I just want you to be safe. That was not safe," she replied, referring to his handling of the gun.

Hunter Biden's attorney Abbe Lowell objected to Jensen's testimony regarding the text messages -- which had been obtained by a court-issued subpoena -- arguing that Hallie Biden would be questioned when the government calls her as a witness.

Prosecutors concluded their questioning of Jensen, after which the defense began its cross-examination.

The jury of 12 jurors and 4 alternates has been seated in Hunter Biden's federal gun trial.

The panel was picked from 250 prospective jurors who arrived at the courthouse this morning for the voir dire process.