Under cross-examination by defense attorney Abbe Lowell, gun store clerk Gordon Cleveland testified about the sequence of events on Oct. 12, 2018, when he sold Hunter Biden the handgun at the center of the case -- with Cleveland and Lowell at times squabbling over details as granular as the direction of Hunter Biden's vehicle when he drove into the store's parking lot.

Cleveland will return to the stand Thursday morning when proceedings continue.

Prosecutor Derek Hines told the judge before court concluded for the day that he anticipated resting his case as soon as the end of the day on Thursday. The government has six brief witnesses remaining, he said.

Lowell said that if the government rests its case by the end of the day Thursday, he would be prepared to call his first witness on Friday morning.

Gun store clerk Gordon Cleveland testified that he watched from "about two feet" away as Hunter Biden, in the course of purchasing a handgun in 2018, filled out Form 4473 and checked the box asking applicants whether they were active drug users.

After Hunter Biden selected the Colt Cobra for purchase, Cleveland said he asked him to fill out Form 4473, which he told him was required for "every gun purchase." Cleveland testified that he instructed Hunter Biden to write in his personal information and answer the questions below, "and to take your time answering them," he said.

Cleveland testified that he watched as Hunter Biden answered several questions on the form before he approached question 11.E., which asked about drug use.

"You saw him strike that box with an 'X'?" prosecutor Derek Hines asked.

"Yes," Cleveland said.

"He didn't seem to express any confusion by that question?" Hines asked.

"No," Cleveland said.

With gun store employee Gordon Cleveland on the witness stand, members of the jury saw the Colt Cobra .38 Special that Hunter Biden purchased from Cleveland on Oct. 12, 2018, at StarQuest Shooters in Wilmington, Delaware.

Prosecutor Derek Hines said the encased gun was rendered safe by marshals and asked the judge to allow him to approach with the weapon.

He first brought the gun to the witness stand where Cleveland read aloud the serial number, and then took it to the jury box, where jurors saw the gun that prosecutors argue Hunter Biden obtained illegally by lying on a federal form.

Prosecutors then moved on to question Cleveland about Form 4473, the form that Hunter Biden filled out when he purchased the gun.

Defense attorney Abbe Lowell, cross-examining Hunter Biden's former girlfriend Zoe Kestan, sought to renew his argument that Hunter Biden was not actively using drugs in October 2018 by emphasizing that Kestan wasn't in contact with him at that time and would not know.

Kestan testified that she wasn't in touch with Hunter Biden from Sept. 23, when they were in Malibu together, until November, when he summoned her to Massachusetts while he was trying out a new ketamine therapy program.

As such, Kestan testified she had "no idea" that he had gone back to Delaware, or what he was doing at that time.

"So you didn't see him between those two dates?" Lowell asked.

"No," she said.

Lowell also sought to cast Kestan as an enabler of Hunter's addiction.

"You helped him get drugs?" Lowell asked.

"Yes," Kestan responded.

Prosecutors pushed back on that argument by highlighting their significant age gap: Kestan was 24 at the time of the relationship, while Hunter Biden was 48.

"Twice my age," she testified.

Kestan subsequently concluded her testimony and stepped down from the witness stand. Prosecutors then prepared to called to the stand Gordon Cleveland, the gun shop employee who sold Hunter Biden the firearm in 2018.

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."