Hunter Biden's defense team encountered significant hurdles just before the commencement of his federal gun trial. On Sunday, Judge Maryellen Noreika issued two crucial rulings that could severely impact the defense's strategy. These rulings excluded a key expert witness and blocked the use of critical evidence that Hunter Biden's lawyers had hoped to present to the jury.

Hunter Biden, the son of President Joe Biden, is facing charges of illegally purchasing and possessing a firearm while being an unlawful user of controlled substances. He has pleaded not guilty to all charges. The trial is set to begin with jury selection on Monday in Wilmington, Delaware.

One of the defense's setbacks came when Judge Noreika granted special counsel David Weiss's request to exclude testimony from Dr. Elie Aoun, a psychiatrist from Columbia University. The defense had planned to use Dr. Aoun's testimony to challenge the prosecution's assertion that Hunter Biden was aware of his addiction when he purchased the firearm in 2018. Noreika ruled that the defense's disclosure regarding Dr. Aoun's testimony was inadequate, leaving the prosecution unprepared to counter his opinions.

"The inadequacy of Defendant's expert disclosure for Dr. Aoun leaves the government in the dark as to what his opinions about the facts of this case will be, thus rendering the government unable to prepare for trial," Judge Noreika wrote.

In addition to blocking Dr. Aoun's testimony, Judge Noreika also ruled against the defense's use of an altered version of the federal firearms form that Hunter Biden filled out when he bought the gun. This form had been modified by gun store employees in 2021. Hunter Biden's lawyers argued that the altered form was essential to undermining the credibility of the employees, who are expected to testify for the prosecution, and to show potential political bias.

However, Noreika found the altered form to be "irrelevant and inadmissible." She criticized the defense for presenting "unsupported rhetoric" and "conspiratorial" theories about the motivations of the gun store employees. "Any probative value it arguably has is substantially outweighed by a danger of unfair prejudice, confusion of issues, and misleading the jury," she wrote.

These rulings mean that only the original ATF Form 4473, where Hunter Biden is accused of falsely claiming he was not using or addicted to drugs, will be presented to the jury. Prosecutors argue that Biden was addicted to crack cocaine at the time, a fact he has admitted to in his memoir.

Jury selection for the trial begins amidst these legal battles. The trial follows nearly a year after a proposed plea deal between Hunter Biden and prosecutors fell apart, a deal that was criticized as overly lenient by congressional Republicans.

The indictment alleges that Hunter Biden purchased a Colt Cobra revolver on October 12, 2018, while knowingly making false statements about his drug use. The charges could lead to a maximum prison sentence of up to 25 years, with significant fines and supervised release periods.

Hunter Biden's legal troubles extend beyond the gun charges. He faces a separate federal tax trial in California, scheduled for September, where he is accused of failing to pay $1.4 million in taxes over four years and filing false tax reports. He has pleaded not guilty to those charges as well.

Judge Noreika has limited the scope of evidence that can be used in the gun trial, excluding references to Hunter Biden's discharge from the Navy for drug use and his child support case for his daughter in Arkansas. The prosecution can use excerpts from Hunter Biden's book to demonstrate his drug addiction but will not introduce the entirety of the infamous laptop that surfaced before the 2020 presidential election.

Hunter Biden's personal life and legal issues have been a persistent source of controversy and political ammunition against President Biden. This trial, with its high-profile nature and the potential implications for the Biden family, is being closely watched by both political supporters and opponents. As the trial unfolds, it is expected to generate significant public and media attention, further intensifying the spotlight on the Biden family's legal and political challenges.