Delaware state trooper Joshua Marley, testifying for the prosecution, described his role in investigating a report of a "stolen gun" on Oct. 23, 2018.

He said that at the time that he believed Hunter Biden "was the victim of the crime."

The gun turned out to have been discarded by Hallie Biden after she discovered it in her then-boyfriend Hunter Biden's car.

Marley spent only a short time on the stand before stepping down.

The government has four witnesses left before resting its case, meaning they will likely continue into Friday morning.

Defense attorney Abbe Lowell continued to probe Hallie Biden's memory of the period in 2018 when she discovered the gun purchased by then-boyfriend Hunter Biden, at one point remarking that there are "some things you remember and other things you don't."

She testified that for most of the month of October 2018 she did not see Hunter Biden abusing alcohol or drugs.

She also said that in the period after she disposed of the gun and filed a police report, her relationship with Hunter was "more tense."

When her testimony concluded, she stepped off the stand.

The government next called Delaware State Police officer Joshua Marley as its next witness.

Under cross-examination from defense attorney Abbe Lowell, Hunter Biden's former girlfriend Hallie Biden said some of her memories of their interactions from the time of the gun purchase are vague.

Lowell began his questioning by saying he understood that it was a "fairly upsetting" period and that "being here is no picnic either."

Hallie Biden conceded that "it's difficult to recall" exactly where Hunter was at specific moments or whether he was where he suggested he was, at one point saying that "it's all kind of vague."

"Reconstructing this is not easy?" Lowell asked her.

"Correct," she replied.

Hallie Biden, the widow of Hunter Biden's late brother Beau Biden, testified that the "remnants" of crack she found in Hunter Biden's car on Oct. 23, 2018 -- the day she discovered then discarded the firearm -- could have been from weeks or months earlier.

"You didn't see him doing drugs or alcohol" the day you discarded the gun, Lowell inquired.

"Correct," she said.

At one point Lowell's cross-examination descended into a bit of chaos as both Lowell and Hallie Biden struggled to follow the proper protocols to get her text messages admitted into evidence.

"So far so good," Abbe said at one point.

"Well, no," prosecutor Leo Wise objected.

Jurors rubbed their eyes and gazed around as the back-and-forth continued, with the courtroom bursting into laughter on several occasions. At one point, Hallie Biden appeared to look over at her fiancé sitting in gallery, shrugging her shoulders and appearing to mouth the words "I don't know."

Court was subsequently recessed for lunch.

Prosecutor Leo Wise read through text messages Hunter Biden's then-girlfriend Hallie Biden exchanged with him in the days following his gun purchase and on the day that she discovered and discarded it, asking her on the stand to provide context for their communications.

Within days of buying the gun, Hunter Biden texted her that he was about to meet a drug dealer named "Mookie." Hallie Biden testified that she thought that to mean "that he was buying crack cocaine."

In another message, Hunter Biden wrote that he was "buy" and then seconds later added "ing." Asked how she interpreted that message, Hallie Biden said, "I mean, I would guess but I didn't know for sure."

In the messages, Hallie Biden repeatedly expressed concern for him, at one point saying explicitly that she didn't want him to die. Wise asked her if she was worried that he would overdose on drugs.

She said "Yes," but added that she was also worried he might die by "suicide, I didn't know."

Wise then asked her to describe the messages the two exchanged on the morning she threw the gun away.

"It's hard to believe anyone is that stupid," Hunter Biden wrote to her.

"He was angry with me" for discarding his gun and putting him in legal jeopardy, Hallie Biden told jurors.

"I'm a liar and a thief and a blamer and a user and I'm delusional and an addict," Hunter Biden texted her.

She texted back, "Let's do this right," and suggested "working on sobriety" together.

Asked what she meant by "sobriety" -- alcohol or drugs or both -- Hallie Biden replied, "Well, if you're sober, it's all of the above."

Prosecutors have introduced Hunter Biden's infamous laptop as evidence while questioning FBI agent Erika Jensen, their first witness.

Prosecutors asked Jensen about email messages found on the laptop and in Hunter Biden's iCloud account that appear to be about his drug use in 2018.

The government had said in pretrial court filings that it was planning to introduce materials on the laptop as evidence in the case.

The laptop has become a symbol of the legal and political controversy surrounding the president's son in recent years. Attorneys for Hunter Biden had previously attempted to preclude the laptop as evidence in the trial, arguing that they have "numerous reasons to believe the data had been altered and compromised before investigators obtained the electronic material."

But special counsel David Weiss argued in court filings that attorneys for Hunter Biden had not "provided any evidence or information that shows that his laptop contains false information," and the judge agreed to admit it as evidence.

Data from the laptop was purportedly obtained and later disseminated in 2019 by a Wilmington, Delaware, computer repairman after the laptop had been dropped off at his shop for repair.

With that context in mind, prosecutors did not rely on the laptop on its own; investigators said they cross-referenced every email, WhatsApp message, iMessage, and text message with Apple Inc. to establish the credibility of the data.

"Ultimately, in examining that laptop, were investigators able to confirm that it was Hunter Biden's laptop?" prosecutor Derek Hines asked Jensen.

"Yes," Jensen said.

"How?" Hines asked.

"Among other things, there was a serial number that's on the back of this laptop that matches the Apple subpoena records that they obtained in 2019, so it matches the registration of this particular device to the iCloud account at a particular date," Jensen said.

"So from the data from the laptop and the hard drive, did you -- what did you do next, or what did the FBI do next when assessing the addiction evidence?" Hines asked.

"So from the data that was extracted from both the iCloud back ups and this -- the laptop, investigators were able to go through largely WhatsApp messages, iMessages, and text messages, and found evidence of addiction within the messages," Jensen said.

Prosecutors also showed jurors an invoice for $85 from the computer repair shop where Hunter Biden dropped off the laptop for repair, which had been sent to an email address belonging to Hunter Biden.

"You said Apple Inc. provided that ... from the iCloud?" Hines asked.

"Yes," Jensen said.