Hallie Biden, Hunter Biden's former romantic partner who is the widow of his brother Beau Biden, has taken the stand as the prosecution's next witness.

Prosecutors have said they expect her to testify about Hunter Biden's drug at the time of his gun purchase in October 2018.

Before gun store clerk Gordon Cleveland stepped off the stand, he testified that Hunter Biden did not exhibit any symptoms of drug or alcohol abuse when he purchased the gun at the center of the case.

When asked by defense attorney Abbe Lowell if Hunter Biden exhibited any symptoms at the time of his gun purchase, such as being "glassy eyed" or smelling of alcohol, Cleveland replied, "None at all."

Cross-examining gun store clerk Gordon Cleveland, defense attorney Abbe Lowell asked about the framing of the various questions on the gun form that Hunter Biden is accused of lying on -- including the difference between "have you" and "are you."

The form, for example, asks the applicant if they "have ever" been convicted -- but asks "are you" an unlawful user of drugs.

The defense team has used this to argue that Hunter Biden could have reasonably believed he was not violating any laws when he checked "No" on the drug-use box, because they say he was not currently using drugs.

"It does not say, 'Have you ever,"' Lowell said.

In court today, Hunter Biden has been attentive and focused, watching as attorneys clashed earlier over evidence. He gripped his pen as prosecutor Leo Wise asked the judge to keep out texts that his team wishes to use when they cross-examination Hallie Biden.

Special counsel David Weiss, who brought the case, has been seated in the front row behind his prosecution team, periodically nodding along as they make their arguments.

Gordon Cleveland, the gun store clerk who sold Hunter Biden the firearm at the center of the case, returned to the stand.

Cleveland was being cross-examined by the defense after testifying for the prosecution yesterday.

Hallie Biden, Hunter Biden's former romantic partner who is the widow of his brother Beau Biden, is expected to be the next witness following Cleveland.

Court resumed this morning with a sidebar conference.

Prosecutors and defense attorneys were arguing before the judge about an exhibit the defense wants to introduce when Hallie Biden, Hunter Biden's former romantic partner, takes the stand as expected later today.

Separately, defense attorney Abbe Lowell signaled his intention to file a motion to have the case thrown out after the government rests.

The long-shot bid will be filed on grounds of constitutional shortcomings and insufficient evidence, Lowell said.

Lowell also said his witnesses -- which could include President Joe Biden's brother James Biden and Hunter Biden's daughter Naomi Biden -- may not be available until Friday morning.

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."