Federal prosecutors on Tuesday painted President Joe Biden's son Hunter as deceptive and driven by addiction, a man whose dark habits ensnared loved ones and who knew what he was doing when he lied on federal forms to purchase a gun in 2018.

"No one is allowed to lie on a federal form like that, even Hunter Biden," prosecutor Derek Hines said Tuesday, telling the jury that they should make "no distinction for Hunter Biden or anybody else" when coming to their verdict.

"He crossed the line when he chose to buy a gun and lied about a federal background check," said Hines, adding that Hunter Biden's "choice to buy a gun is why we are here."

Defense attorneys said Tuesday they would call James Biden, Hunter Biden's uncle and President Biden's brother, to the stand. James Biden helped his nephew through stints in rehab.

“You will see that he is not guilty," Hunter Biden's attorney Abbe Lowell said in his own opening statement, saying that his client "did not knowingly violate these laws" and "has never asked anyone to excuse his mistakes."

Hunter Biden has been charged with three felonies stemming from the purchase of the Colt revolver when he was, according to his memoir, addicted to crack. He has been accused of lying to a federally licensed gun dealer, making a false claim on the application by saying he was not a drug user and illegally having the gun for 11 days.

Prosecutors told the jury in their opening statement that Hunter Biden was trying to score drugs just days after he lied on the form, telling his brother’s widow, Hallie Biden, in a message that he was waiting for a drug dealer. The jury heard lengthy audio excerpts of Hunter's 2021 memoir "Beautiful Things" where he described his extensive drug use, yearslong addiction to crack, stints at rehab and how he learned to cook crack.

The prosecution's first witness, an FBI agent, walked jurors through various aspects of the audio to provide context. Some jurors were seen yawning as the extended clips played. Hunter Biden sat mostly still throughout, nodding at the end of one clip.

The case is dredging up painful memories for the president and his family, and revealing new and highly personal details about their struggles with addiction as the 2024 election looms, all while the first lady watched from the front row of the courtroom.

Jurors heard how Hallie Biden also became addicted to crack during a brief relationship with Hunter. Hallie took the gun from Hunter and tossed it into the garbage at a nearby market, afraid of what he might do with it. The gun was later found by someone collecting cans and eventually turned over to police.

The president was in Washington on Tuesday, announcing an immigration order and hosting a picnic for congressional leaders before a scheduled departure for France later in the day. He will be gone the rest of the week. Jill Biden planned to meet him in Europe.

The president's allies are worried about the toll the trial may take on the elder Biden, who's long been protective and deeply concerned about his only living son and his sobriety and who must now watch as those past mistakes are publicly scrutinized. And the president must do so while he's campaigning under anemic poll numbers and preparing for an upcoming presidential debate with Trump.

Prosecutors on Tuesday spent hours detailing Hunter Biden's addiction to jurors. They showed the 12-person panel an old laptop computer, the same one he left at a Delaware repair shop and never retrieved. In 2020, the contents made their way to Republicans and were publicly leaked, revealing highly personal messages about his work and his life. He has since sued over the data breach.

His sister Ashley Biden, watching from the courtroom, dabbed at her eyes with a tissue and eventually left. Jill Biden, too, was absent after lunch. She was expected in Washington with her husband.

An FBI agent read aloud text messages to the jury of Hunter Biden desperately seeking to buy drugs, email receipts for a detox facility he attended before relapsing and large sums of cash he withdrew.

The proceedings come after the collapse of a deal with prosecutors that would have avoided the spectacle of a trial so close to the 2024 election. Hunter Biden pleaded not guilty and has argued he's being unfairly targeted by the Justice Department after Republicans decried the now-defunct plea deal as special treatment for the Democratic president's son.

Lowell said the form asks whether you "are" a drug user. "It does not say 'have you ever been,'" and he suggested the president's son did not think of himself as someone with a drug problem when he purchased the gun.

His state of mind should be considered at the time of the purchase, not "what he wrote in a book in 2021."

Lowell also blamed Hunter's problems with the firearm on Hallie's disposal of it.

"After he bought the gun, Hunter did nothing with it," Lowell said. The gun became a problem only because of what Hallie Biden did.

If convicted, Hunter Biden could face up to 25 years in prison, though first-time offenders do not get anywhere near the maximum, and it's unclear whether the judge would give him time behind bars.

The trial is unfolding just days after Donald Trump, the presumptive Republican presidential nominee, was convicted of 34 felonies in New York City. The two criminal cases are unrelated, but their proximity underscores how the courts have taken center stage during the 2024 campaign.

A former Trump aide and vocal Biden critic, Garrett Ziegler, has been attending the proceedings. On Tuesday, Hunter's wife, Melissa, pulled him aside and told him curtly that he did not belong there.

Ziegler has been sued by Hunter Biden, who claimed he violated computer privacy laws by accessing and then manipulating the laptop data.

Hunter Biden also faces a trial in California in September on charges of failing to pay $1.4 million in taxes. Both cases were to have been resolved through the deal with prosecutors last July, the culmination of a yearslong investigation into his business dealings.

But Judge Maryellen Noreika, who was nominated to the bench by Trump, questioned some unusual aspects of the deal, which included a proposed guilty plea to misdemeanor offenses to resolve the tax crimes and a diversion agreement on the gun charge, which meant as long as he stayed out of trouble for two years the case would be dismissed.

The lawyers could not come to a resolution on her questions, and the deal fell apart. Attorney General Merrick Garland then appointed the top investigator, a former U.S. attorney for Delaware, David Weiss, as a special counsel in August, and a month later Hunter Biden was indicted.

Garland on Tuesday faced members of the Republican-led House Judiciary Committee in Washington, which has been investigating the president and his family and whose chairman has been at the forefront of a stalled impeachment inquiry stemming from Hunter Biden's business dealings.

Spectrum News' Ashley Gallagher and Taylor Popielarz contributed to this report.