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.

In July 2023, a plea deal struck between Hunter Biden and prosecutors that could have precluded this week's trial dramatically fell apart amid the judge's concerns over the terms of the agreement.

For the better part of three hours, U.S. District Judge Maryellen Noreika scrutinized nearly every facet of the plea deal. Noreika acknowledged that her probing threw "a little bit of a curveball" into the proceeding.

Hunter Biden had originally agreed to a pretrial diversion on the gun charges, with the charges being dropped if he adhered to certain terms. He had also agreed to acknowledge his failure to pay taxes on income he received in 2017 and 2018. In exchange, prosecutors would have recommended probation on those charges.

Democrats had hailed the deal as a sign of accountability while Republicans panned the details as a "sweetheart deal."