Chemist Jason Brewer, testifying as an expert witness for the prosecution, told the jury that a brown leather pouch that contained Hunter Biden's gun at the time the weapon was retrieved by authorities tested positive for cocaine.

Brewer said there were "minimal amounts of white powder" on two locations on the pouch, which he combined and tested.

On cross-examination, Hunter Biden's attorney sought to raise doubts about how that white powder got there and who put it there -- emphasizing it could have been old, dating back to before Hunter Biden purchased the gun.

"You can't date when it got there?" defense attorney David Kolansky asked.

"I cannot," Brewer said.

Kolansky also emphasized that five years went by from the time the pouch was collected in October 2018 to when it was tested in October 2023 -- after the indictment in this case was already filed.

He emphasized the importance of the "chain of command," which Brewer conceded was "very important."

Earlier, Hunter Biden's former girlfriend Hallie Biden testified that she put the gun in the pouch, which she found in Hunter Biden's vehicle, after she discovered the weapon in the vehicle and before she disposed of it in a trash container.

Proceedings resumed this morning with the government calling FBI chemist Dr. Jason Brewer to the stand.

Brewer is testifying as an expert witness.

Prosecutors said they would then call a DEA officer as their final witness.

First lady Jill Biden, Hunter Biden's stepmother, is in attendance at the trial this morning.

She returned from France, where she was accompanying President Joe Biden on a trip to mark the 80th anniversary of D-Day.

She had attended the trial each day until making the trip to France.

Hunter Biden has arrived at the courthouse for Day 5 of the trial.

He was accompanied as usual by his wife Melissa Cohen Biden.

Attorneys for Hunter Biden, in their cross-examination of FBI Special Agent Erika Jensen, attempted to push back on prosecutors' contention that Hunter Biden was abusing drugs at the time he said on a gun-purchase form that he was drug-free.

A key piece of evidence comes from Hunter Biden's 2021 memoir, in which he described his "relapse" just weeks after leaving rehab in August -- just six weeks before purchasing the firearm.

"I stayed clean for two weeks then relapsed," Hunter Biden wrote in his book.

Defense attorney Abbe Lowell, on cross-examination, questioned the assumption that Hunter Biden's relapse implied that he was referring to his drug use -- suggesting instead that he was referring to his alcohol addiction.

"When he was referring to that in his book, was he talking about relapsing to drugs and alcohol, or do you know what he meant?" Lowell asked.

"I can only state what was stated," Jensen said.

"Which is, 'Then I relapsed?'" Lowell asked.

"Just what it says, 'I relapsed,'" Jensen replied.

Jensen also acknowledged that she could not verify that Hunter Biden was continuously using drugs from 2015 to 2019, saying, "My recollection is that there are excerpts where he was principally occupied with smoking crack cocaine. I didn't get the sense that it was the entire history."

"Meaning that there were periods of time that he was not?" Lowell asked.

"I think there -- including the period in August where we have some invoices for rehab, that there were periods where there was not," Jensen said.

It was an important moment for the defense, as Lowell managed to establish that Hunter Biden's use of drugs was not consistent -- cuing up his argument that the president's son was not on drugs at the time of his firearm purchase.

Prosecutors also entered into evidence records related to enormous cash withdrawals Hunter Biden made -- more than $150,000 from September through November of 2018, including a $5,000 withdrawal on the day he purchased the gun. Prosecutors suggested this cash was used to procure drugs; Lowell, on cross-examination, established that Hunter Biden paid $900 in cash for the weapon and accessories.

Court was subsequently recessed for the day, with Lowell's cross-examination of Jensen scheduled to resume Wednesday morning.

Prosecutors suggested that Hallie Biden would be the next witness after Jensen, making it likely that the first Biden family member to testify will take the stand at some point tomorrow.