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.

Prosecutor Leo Wise used witness testimony and Hunter Biden's own words from his memoir and text messages to argue that the president's son "knew exactly what he was doing" when prosecutors say he falsely claimed he was not addicted to drugs in order to purchase a Colt handgun in 2018.

"Take the defendant's word for it," Wise said as he showed the jury excerpts from Hunter Biden's book that described his drug use and addiction.

Wise, showing the jurors a side-by-side comparison of testimony regarding his truck from his daughter Naomi Biden and then-girlfriend Hallie Biden, said their testimony is "circumstantial evidence " that shows "the defendant used crack in the truck" days after purchasing the firearm.

Naomi Biden testified that she returned the truck to her father "clean" on Oct. 19, 2018, and Hallie Biden testified that a few days later she found Hunter Biden's gun in the vehicle along with drug paraphernalia and drug remnants.

Wise also showed the jury a calendar of the month of October 2018 that showed the cash withdrawals made by Hunter Biden. "None of the cash was for rehab," Wise said.

The evidence, Wise told jurors in conclusion, "supports only one verdict."

Hunter Biden's attorney Abbe Lowell then began his closing arguments.