Hunter Biden has arrived at the Wilmington courthouse for today's proceedings.

Like previous days, he was accompanied by his wife, Melissa Cohen Biden.

The gun store clerk who sold Hunter Biden the handgun at the center of the government's case returns to the witness stand this morning on Day 4 of the trial as prosecutors look to wrap up their case against the president's son.

Prosecutors said at the end of Wednesday's proceedings that they plan to call six more witnesses -- including Hallie Biden, perhaps their most crucial witness -- before resting their case, which could happen as soon as this afternoon.

Defense counsel have leaned into their claim that Hunter Biden was not actively abusing drugs in October of 2018, the month of his gun purchase, and therefore did not knowingly lie on the federal firearm application form.

Zoe Kestan, one of Hunter Biden's ex-girlfriends, testified Wednesday that she witnessed him smoking crack the month before and the month after his gun purchase, but had "no idea" what he was doing in October.

To fill that gap, prosecutors plan to call Hallie Biden, his brother's widow with whom Hunter Biden was romantically involved.

"The evidence will show that during those 11 days, the defendant continued to use drugs and to talk about his drug use with Hallie," prosecutor Derek Hines said.

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.

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."