Special Counsel David Weiss is trying to force Hallie Biden and her sister, Elizabeth Secundy, to testify against Hunter Biden at his upcoming tax trial, where he faces several counts of failing to file and failing to pay his taxes. Ms. Biden was a critical witness for Mr. Weiss in his successful prosecution of the first son in Delaware for illegally purchasing a firearm while addicted to crack cocaine. 

In two court filings sent to Judge Mark Scarsi of the Central District of California, Mr. Weiss and his lead attorneys, Leo Wise and Derek Hines, say Ms. Biden and Ms. Secundy’s testimonies “may be necessary to the public interest.”

If Judge Scarsi approves the motion to compel the testimony from both women, they will be granted immunity — just as Ms. Biden was in the Delaware case — from prosecution for any potential crimes they describe on the stand. In asking the judge to compel the women’s testimony, Mr. Weiss invokes a federal law that states: “No testimony or other information compelled under the order … may be used against the witness in any criminal case, except a prosecution for perjury, giving a false statement, or otherwise failing to comply with the order.”

During the Delaware trial, Ms. Biden described her relationship with the first son at the time he bought the gun, admitting that he had gotten her addicted to smoking crack. Ms. Biden said it was “terrible” and that she is “embarrassed” and “ashamed” about that period of her life. After using the drug for several months, Ms. Biden says she quit in August 2018. As they were dating at the time, she may be able to provide some insight into Biden’s finances when he was allegedly dodging taxes. 

Ms. Secundy, who appeared to have a close relationship with the first son, based on emails and texts recovered from his laptop, has been investigated by the House impeachment inquiry over her financial relationship with Biden — specifically, why she received tens of thousands of dollars from the first son and his company, Owasco P.C., without providing known services. 

“The Committees have reviewed bank records that show you have received tens of thousands of dollars from Hunter Biden directly, and through his professional corporation, Owasco P.C. We are aware that Hunter Biden used Owasco, P.C. to receive proceeds from foreign nationals,” the impeachment committees wrote in a letter to Ms. Secundy last year. They said they were seeking “to understand the services you may have provided Owasco P.C.,” as well as “clarification as to why you received this money from Hunter Biden.”

Mr. Weiss and his deputies have been filing a number of motions to exclude evidence and arguments from the upcoming tax evasion trial, hoping to head off any sob stories or emotional pleas about Biden dodging taxes simply because he was in the throes of addiction at the time he was not paying his bills. 

In one of their recent motions, the prosecution argued that Biden should not be allowed to invite a substance abuse expert to testify at trial about the struggles and complexities of addiction. 

The expert in question, Joshua Lee, as well as the defense’s backup expert, Elie Aoun, should not be allowed to take the stand given the lack of clarity about their beliefs or their relationship with Biden, the prosecutors say. “What is Dr. Lee’s opinion of how persons with addiction behave? The notice does not say,” Mr. Weiss writes. “To state the obvious, what is this analysis? It’s not in the notice. And what is his opinion about the defendant following Dr. Lee’s view based on? Which statements did Lee review and analyze?”

Dr. Aoun was not accepted as an expert witness at the Delaware trial in June, which Mr. Weiss says is evidence enough to keep him from testifying at this trial. 

The prosecution also says the defense’s supposed tax law expert, Thomas Bishop, should be barred from taking the stand because — like Dr. Lee and Dr. Aoun — he has failed to disclose his specific opinions about tax law or Biden’s current circumstance to the court. 

Mr. Weiss is asking Judge Scarsi to forbid Biden’s attorneys, Abbe Lowell and Mark Geragos, from making the argument during the trial that Biden is the victim of a vindictive or politically motivated prosecution. Mr. Lowell has previously tried to get his argument before the jury, both in the upcoming California case and at the previous Delaware one. The defense had hoped to compare Biden’s situation to that of others who have avoided their taxes and who were subject to civil actions or fines, not criminal prosecution. 

Mr. Lowell had also hoped to argue that the “sweetheart” plea deal crafted by the defense and Mr. Weiss in 2023 could be reinstated, or that it could be mentioned at trial. The special counsel has asked Judge Scarsi to forbid the mention of that deal. 

On Wednesday, Mr. Weiss filed with the court his exhibit list, which includes more than 250 pieces of evidence such as emails, text messages, purchase histories, and bank statements. Among the evidence listed are thousands of dollars in tuition sent by Biden to Columbia University for his daughter’s tuition, credit card payments, and a $10,000 membership fee at a country club. Biden’s venmo transactions — presumably showing large payments at a time when he was failing to pay his taxes — will also be included. 

Messrs. Lowell and Geragos, for their part, filed motions to exclude certain facts from trial, including any mention of Biden’s discharge from the Navy or allegations that he was illegally acting as a foreign agent. They also hope the prosecution won’t be allowed to mention any of Biden’s more “extravagant” purchases, though they did not disclose what exactly those were in their court filing.