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.

Defense attorney Abbe Lowell, in his closing argument, urged jurors to dispense with the government's "conjecture and suspicion" and find his client not guilty on all three counts.

"We have had Hunter's life in our hands" until now, Lowell said, referring to his legal team. "And now we have to give it to you."

Lowell repeatedly referred to prosecutors' case as a "magicians' trick" -- to "watch this hand and pay no attention to that one," as he said -- arguing that prosecutors failed to "fill in the gaps" about Hunter Biden's drug use around the time of his firearm purchase "because they don't have the proof."

Lowell also referred to prosecutors' strategy of showing Hunter Biden's pattern of drug use as an "accordion," meant to "compress" the timeline and make it seem to jurors that he was actively using drugs in October 2018, when he said on a government form that he was not addicted to drugs in order to purchase a Colt handgun.

The defense attorney also attacked some of the tactics prosecutors used, calling their treatment of Hunter Biden's daughter Naomi Biden "extraordinarily cruel" and saying that many of their questions and evidence were introduced with the intention of "embarrassing Hunter."

He also asked jurors to recall gaps in the recollections of Hunter Biden's then-girlfriend Hallie Biden, and suggested they should remember the immunity agreement she struck with prosecutors for her testimony.

"These are serious charges that will change Hunter's life," he said of the three felony charges the president's son faces, adding that "it's time to end this case."

Following Lowell's closing, the government was scheduled to have a short rebuttal, at which point the judge was to finish her jury instructions before the jury gets the case.