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.

Taking the stand as a prosecution witness, Hunter Biden's ex-wife Kathleen Buhle described how, after 25 years, their marriage deteriorated under the weight of his drug and alcohol addiction.

Buhle said she first learned of Hunter Biden's crack addiction when she discovered an empty crack pipe in an ash tray on their side porch the day after their anniversary in 2015. Hunter Biden was kicked out of the Navy in 2014 for testing positive for cocaine, and Buhle said ever since then she was "worried, scared" he would abuse drugs again.

When he was on crack, Buhle testified, "He was not himself … angry, short-tempered, acting in ways he wouldn't when he was sober."

She said she would find drug "remnants in little bags" and drug paraphernalia like "a broken crack pipe" -- often enough that she would search his car before allowing her daughters to use it.

In what could be a blow to one of Abbe Lowell's lines of defense, Buhle said Hunter Biden frequently interacted with friends and family, worked, and socialized while under the influence of crack cocaine -- and would often try to hide it from those close to him.

"Did you see him, for lack of a better word, function?" prosecutor Leo Wise asked.

"Yes," Buhle confirmed.