WILMINGTON, Del. (AP) — Jurors who will decide whether President Joe Biden’s son is guilty of federal firearms charges are hearing deeply personal testimony about a dark period for Hunter Biden.

The case playing out in the federal court in Wilmington, Delaware, stems from a gun the younger Biden bought in October 2018, months before his father announced his bid for the presidency.

Prosecutors say Hunter Biden lied when he swore he wasn’t a drug user on a federal form he filled out at the gun shop. He had the gun for about 11 days before it was thrown in a trash can.

Hunter Biden’s attorney argues his client did not believe he was in the throes of addiction when he stated in the paperwork that he did not have a drug problem.

Hunter Biden was supposed to have avoided prosecution in the gun case altogether, but a deal with prosecutors fell apart last year. He was subsequently indicted on three felony gun charges. He also faces a trial scheduled for September on felony charges alleging he failed to pay at least $1.4 million in taxes over four years.

Here’s a look at some key witnesses in the trial:

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KATHLEEN BUHLE

One of the prosecutors’ first witnesses was Hunter Biden’s ex-wife, who filed for divorce in 2016 after more than 20 years of marriage. They have three children together. In divorce proceedings, she accused him of squandering their money on drugs, alcohol, strip clubs and prostitutes.

On the witness stand, Buhle described learning about Hunter Biden’s drug use when she found a pipe used to smoke crack cocaine in an ashtray on their porch in July 2015, weeks after Hunter’s brother Beau died from brain cancer.

When she confronted Hunter, he “acknowledged smoking crack,” she told jurors.

Buhle testified that she suspected that Hunter was using drugs even before she found the crack pipe, given that he earlier had been kicked out of the Navy after testing positive for cocaine.

“I was definitely worried, scared,” said Buhle, who was subpoenaed by prosecutors.

She also recounted searching the family’s car for drugs whenever her children were driving it. But she acknowledged under questioning from Hunter’s attorney that she never actually saw him using drugs.

HALLIE BIDEN

A key witness expected to take the stand for prosecutors is Beau’s widow, who had a romantic relationship with Hunter Biden after his brother’s death.

When their relationship became public in 2017, Joe Biden and his wife Jill said in a statement that the couple had their “full and complete support,” adding: “We are all lucky that Hunter and Hallie found each other as they were putting their lives together again after such sadness.”

Hunter detailed their troubled romance in his memoir “Beautiful Things,” writing: “As much as we desperately thought we could be the answers to each other’s pain, we only caused each other more.”

Hallie Biden found the gun in Hunter Biden’s truck days after he bought it and threw it in a trash can near a grocery store in Wilmington. Hunter Biden told police in 2018 that she took the gun because she was concerned about his mental health, according to a police report.

Hunter got upset when he found out she threw the gun away, but it was no longer there when she went back to look for it. A man collecting recyclables found it and gave it to the police.

Jurors have already seen text messages between the pair that prosecutors are using to try to prove that Hunter Biden knew he was addicted to drugs when he said on the form he wasn’t.

In one late-night exchange shortly after he bought the gun, Hallie asked Hunter where he was. Hunter replied he was behind a baseball stadium in downtown Wilmington “waiting for a dealer.”

ZOE KESTAN

Kestan, another former romantic partner, was given immunity in exchange for her testimony to prosecutors.

She described meeting Hunter in December 2017 at a strip club in New York where she was working. During a private session with her and another girl, he pulled out a pipe and began smoking what she assumed was crack, she testified.

“He was incredibly charming and charismatic and friendly, and I felt really safe around him,” she said. “I remember after he had smoked it, nothing had changed. He was the same charming person.”

The two met up again a couple of weeks later in New York. She recounted staying at his hotel for five days, a period in which she says Hunter Biden smoked cracked perhaps every 20 minutes. At one point during their stay together, he asked her to go meet his drug dealer and bring him up to the room, she told jurors.

But Kestan acknowledged she had no contact with Hunter Biden in October 2018, the month he bought the gun.

JAMES BIDEN

The defense plans to call to the witness stand President Biden’s brother, who is close with Hunter Biden and helped his nephew through rehab stints in the past.

Outside the case, James Biden’s business dealings have made him a target of Republicans, who questioned both him and Hunter Biden in their stalled impeachment inquiry. Joe Biden told lawmakers during a voluntary private interview in February that the president “never had any involvement or any direct or indirect financial interest” in his business ventures.

House Republicans on Wednesday accused Joe Biden and Hunter Biden of making false statements to Congress and sent criminal referrals to the Justice Department. The claim involving James Biden is over a statement he made about whether the president, while a private citizen, met with a former Biden family business partner.

James Biden’s lawyer called the Republicans’ move a “transparent and cynical attempt to distract and retaliate for Donald Trump’s recent criminal conviction.”

Hunter Biden’s lawyer, Abbe Lowell, said it was “nothing more than a desperate attempt by Republicans to twist Hunter’s testimony so they can distract from their failed impeachment inquiry and interfere with his trial.”

GORDON CLEVELAND

Cleveland sold Hunter Biden the .38 caliber revolver at a Wilmington gun shop in 2018.

Testifying for prosecutors, the former gun store clerk told jurors he stood next to Hunter Biden when he began to answer a series of questions on the federal form every person has to fill out when they buy a gun. Hunter checked a box saying he was purchasing the gun for himself, Cleveland said.

Another question asked whether the buyer was “an unlawful user of or addicted to” marijuana, stimulants, narcotics or any other controlled substance. Hunter Biden wrote “no,” Cleveland said.

He also testified that Hunter did not ask any questions or express any confusion about the question. Hunter Biden paid $900 in cash, telling Cleveland to keep the change — about $13.

Cleveland told jurors he watched Hunter sign the form, which includes a warning about the consequences of submitting false information.