WILMINGTON, Delaware — Prosecutors on Tuesday painted a damning portrait of Hunter Biden as “a bloodhound” for crack cocaine — to use the first son’s own parlance — when he purchased a handgun in 2018 and allegedly lied on a federal form about his addiction. An FBI special agent involved in the investigation testified that she and her team felt the excerpts from Mr. Biden’s memoir alone were damning. 

Special Counsel David Weiss’s top deputy, Derek Hines, took to the podium Tuesday morning to describe Mr. Biden as a chronic addict and habitual user of dangerous substances, legal and illegal, that impaired his judgment over the course of several years. 

To begin his opening statement, Mr. Hines, referring directly to Mr Biden’s status as the only surviving son of the American president, used the very phrase Mr. Biden’s father employed to respond to the conviction of President Trump: “No one is above the law.”

To illustrate the severity of Mr. Biden’s active addiction around the time of the handgun purchase, Mr. Hines played about a dozen excerpts — totaling more than an hour of recordings — from Mr. Biden’s 2021 addiction memoir, “Beautiful Things,” which documented his years-long struggle with drugs and alcohol. 

The recordings, which were read by Mr. Biden himself in the 2021 audiobook version, detailed some of the darkest days of the first son’s life — and could help prove to a jury that Mr. Biden was willfully lying to the federal government when he bought the Colt handgun in Delaware in 2018. 

The FBI agent, Erika Jensen, said on the stand that she was a 20-year veteran of the agency and had been involved in investigations into “drugs, gangs, and violent crime.” 

Mr. Hines directed her to printed excerpts from the book that were placed in a binder in front of her before playing the audio recordings for the jury. 

Mr. Hines began his journey in 2016, when Mr. Biden was having an affair with his brother’s widow, Hallie Biden, while also married to his wife of 25 years, Kathleen Buhle, who divorced him in 2017 in an ugly split.

In a recording from the audiobook in which Mr. Biden recounted his struggles in 2016, the first son can be heard detailing how misunderstood he felt by his friends and family at the time, and how he used drugs and alcohol as an escape. “If you knew how good it felt, you wouldn’t look at me like I had three heads,” Mr. Biden said on the tape of the euphoria he experienced from drug use.

At about the same time period, Mr. Biden admitted in his memoir to inviting a homeless woman named Rhea to live in his apartment with him in the District of Columbia. He would send her out to buy crack on the street before bringing it home so they could smoke it together. 

“I’d send her out with $100 to get ten dime bags and I’d let her keep two,” the first son said. He described smoking crack as “indispensable” and said he felt “ecstatic” after doing it. 

Mr. Hines then skipped to late 2016 — shortly before the presidential election — when Mr. Biden was especially struggling. The first son recounted in the 2021 recording how in 2016 he skipped several flights at Dulles airport in Virginia to drink at the bar, only to later decide to drive to Arizona from the East Coast on his own in order to get to rehab. 

He admitted in the book to driving through the night, stopping only in Tennessee to try to buy more crack. Mr. Biden said on tape that his “superpower” was being able to find crack no matter where he was. “I could get off a plane in Timbuktu and score crack,” he said on the audio recording played to a silent courtroom. 

After Mr. Biden found a local gas station attendant in Tennessee who had a crack dealer friend, the first son admitted to spending $1,500 on the drug while staying in town for three days. 

Like at jury selection on Monday, the first son was well-supported by friends and family during Tuesday’s opening arguments and testimony. Mr. Biden’s stepmother, the first lady, Jill Biden, sat directly behind him along with Mr. Biden’s half-sister, Ashley, whom the first lady shares with the president. The first lady sat between Ashley and Mr. Biden’s second and current wife, Melissa Cohen. 

Mr. Biden’s friend and “sugar brother,” Kevin Morris, a successful entertainment lawyer who has been bankrolling Mr. Biden’s lifestyle and legal defense fund for years, was also sitting with members of the Biden family. 

As Mr. Biden’s own voice echoed through the unassuming, wood-paneled, windowless Delaware courtroom for more than an hour on Tuesday, his friends and family remained mostly still. 

Mr. Biden himself stared straight ahead for most of the exhibition, only occasionally looking down or talking to his lead defense attorney, Abbe Lowell. At one point, Ashley could be seen wiping tears from her eyes as a portion of Mr. Biden’s audio book was played where he described the pain of losing his brother and his subsequent manic behavior that drove him to be smoking crack every half an hour. 

After several excerpts of the audio book had been played, Mr. Morris took Ashley Biden’s hand before she got up and left the courtroom. She did not return for the rest of the day. 

Following a lunch break, Mr. Hines then dove into bank records recovered from Mr. Biden’s infamous laptop, which was also unveiled as physical evidence at trial Tuesday. 

Mr. Hines and Ms. Jensen disclosed that Mr. Biden was withdrawing huge sums of money from his personal account before, during, and after he purchased the firearm on October 12, 2018. 

Between September 1 and November 30 of that year, Mr. Biden withdrew more than $150,000 in cash from ATMs. In the 72 hours leading up to his purchase of the Colt handgun, he withdrew a total of $8,600 — even though the firearm, the ammunition, the speedloader, and other supplies he bought on October 12 cost less than $900. 

Toward the end of the day, Ms. Jensen read aloud text messages recovered from Mr. Biden’s phone and laptop to two women in 2018 and 2019. In one expletive-laden text to his then-girlfriend Hallie, he called her a “motherf—.”

In another, to a friend named Ali Kennedy, Mr. Biden called the her a “c—,” which caused Judge Maryellen Noreika to close her eyes and sigh as if she was repulsed by the message. 

Correction: Erika Jensen is the FBI agent who testified today in Hunter Biden’s trial. An earlier version misspelled her name.