The Internal Revenue Service case agent who handled "95%" of the tax evidence in the Hunter Biden investigation told CBS News that he "felt handcuffed" during the five-year probe and blocked from pursuing leads that he thought might implicate Hunter Biden's father, President Joe Biden.
Special Agent Joseph Ziegler, a 13-year veteran of the IRS, is the second IRS employee to come forward to claim the federal tax investigation into the president's son supported criminal charges more serious than the misdemeanor tax charges he is scheduled to plead guilty to next week as part of a plea bargain.
"When you're prevented from going down certain roads, I guess I don't know what could have been found if we were not hamstrung or not handcuffed," Ziegler told CBS News.
Ziegler, who has been known only as "Whistleblower X," revealed his identity Wednesday at the insistence of lawmakers, who called him before a House committee to describe his role in the federal investigation into Hunter Biden. As the main IRS case agent, he worked with his supervisor Gary Shapley and says the evidence they uncovered "supported felony and misdemeanor tax charges."
Ziegler's investigation spanned both the Trump and Biden administrations.
"I'm a Democrat. In the last presidential election, I actually did not vote," Ziegler said. "I thought it would be irresponsible of me to do so because I didn't wanna show bias one way or the other."
An attorney for Hunter Biden, Christopher Clark, has said previously that suggestions the investigation was not thorough are "preposterous and deeply irresponsible."
At Wednesday's hearing, Rep. Jamie Raskin, Democrat of Maryland, said he has not seen evidence that Hunter Biden "received any kind of official favoritism in this prosecution for being Joe Biden's son."
"The key point, Mr. Chairman that America needs to understand is that the only political interference at play here is coming from Donald Trump and my Republican colleagues," Raskin said.
During an executive session in June, the Ways and Means committee voted to publicly release the transcripts from Shapley and Ziegler's whistleblower testimony, keeping Ziegler's identity hidden. The top minority member on the committee, Democratic Rep. Richard Neal of Massachusetts, said during that closed door meeting that Republican efforts to publicize the tax records of a private citizen was an example of "naked partisanship, and stoops below the stature of this Committee."
Democrats have also focused on Shapley's and Ziegler's choice of legal representation; their attorneys have had connections to Republican Party politics. Those attorneys counter that they have worked with both Republican and Democratic whistleblowers and organizations. Democrats also questioned whether the two agents lacked visibility into the factors prosecutors faced when making decisions about what charges to bring. And they noted that Hunter Biden has repaid the taxes he owed.
Ziegler alleges that evidence he collected showed how Hunter Biden improperly claimed business deductions for a range of personal expenses, such as college tuition for his children, bills for stays at a posh Hollywood hotel, payments to escorts, and no-show employees. In 2021, Ziegler says he drafted a memorandum recommending prosecutors charge Hunter Biden with multiple felonies and misdemeanors.
"In August of 2022, we had a phone call with all of the assigned prosecutors and they had said that all four of them were recommending the approval of felony and misdemeanor tax charges," Ziegler said.
Hunter Biden's legal team did not immediately respond to a request for comment.
Ziegler said Trump-appointed U.S. Attorney for Delaware, David Weiss, told him he agreed with certain felony charges, but there was resistance from other officials inside the Department of Justice who thought a jury may be sympathetic to Hunter Biden's drug addiction and the death of his brother, Beau Biden.
"David said to us…'I'm getting some concern from the Department of Justice Tax Division, the evidence that might come in related to his substance abuse and the death of his brother, Beau Biden, those might affect the jury's opinion'," Ziegler said.
Court filings unsealed last month showed that the U.S. attorney's office ultimately agreed to a deal that would charge Hunter Biden with two misdemeanor tax counts — to which the president's son agreed to plead guilty — and a felony gun charge for which Biden agreed to enter into a diversion program. Biden will not plead guilty to the gun charge, which will be dismissed if he meets certain conditions. That deal will have to be approved by a federal judge, who has scheduled a hearing on the matter for next week in Delaware.
"At the end of the day, it's a matter of are we treating everyone the same? Are we treating all taxpayers the same?" Zielger said. "And in this case, no, I don't think so."
The decision not to charge the president's son with tax felonies remains a source of concern and confusion for both of the IRS agents who have now spoken out about the matter. Both men have raised concerns about the possibility that the Biden Justice Department in some way impeded the case.
Weiss pushed back in a letter last month saying he had ultimate authority on these matters and was "never denied the authority to bring charges in any jurisdiction."
The U.S. attorney's office for Delaware declined to comment on this story.
Attorney General Merrick Garland — who kept Weiss on the job to complete the Biden probe — previously said in response to the allegations that Weiss was "permitted to continue his investigation and to make a decision to prosecute any way in which he wanted to and in any district in which he wanted to."
Both Ziegler and Shapely have told congressional investigators and CBS News they were told that prosecutors in Delaware were prevented from bringing charges in other jurisdictions — including California and Washington, D.C. — and Shapley said Weiss told him he was denied special counsel status by the Justice Department.
"D.C. said, 'No, we are not gonna assist you with bringing charges in our district. And we don't think you should bring these charges forward in our district,'" Ziegler explained to CBS News.
During the investigation, Ziegler said he "felt handcuffed." For example, he says he wanted prosecutors to obtain a search warrant to access a Virginia storage unit to search for potential business records but they declined to do so. He said requests to interview Hunter Biden's adult children about the tax payments were frustrated by prosecutors, whom he claims said the requests could "get us into hot water."
Ziegler's requests to pursue a number of investigative avenues came when Trump was still in office and Attorney General William Barr had instituted a policy requiring he personally approve any investigation of a president or presidential candidate. Ziegler told CBS that he was not "aware" of any approvals sought from Barr at that time.
On Monday, after the Committee on Oversight and Accountability interviewed an FBI agent from the Wilmington Field Office, the leading Democrat on the committee, Rep. Jamie Raskin of Maryland, accused Republicans of "distort[ing]" evidence in order "to advance Republicans' false narrative about political interference in the Hunter Biden investigation."
In another instance, Ziegler said he tried to get location data to determine whether Joe Biden was in the room, as his son had boasted in a 2017 WhatsApp message where he appeared to pressure a Chinese businessman to make good on an outstanding payment by mentioning his father.
"I am sitting here with my father..we would like to understand why the commitment made has not been fulfilled," Hunter Biden allegedly texted to the businessman, according to the transcript. He added, "I would like to resolve this now before it gets out of hand" and "now means tonight."
Ziegler said the WhatsApp message was found on Hunter Biden's iCloud account that was obtained through a search warrant. He says he was unable to determine whether Hunter Biden and his father were together when the WhatsApp message was sent. President Biden has said he was never present when any such message was sent and denied any knowledge of this message.
"Anytime we potentially wanted to go down the road of asking questions related to the president, it was 'That's gonna take too much approvals. We can't ask those questions."
Ziegler said he expected extra approvals when investigating the son of a president, but he said the requests went unmet.
There would be a point to where it would be like, 'Well, let's think about it. Let's put that on the back burner.' And it would now move down to item number 50," Ziegler said.
President Biden has denied any involvement in his son's business affairs.
"I have not taken a penny from any foreign source, ever, in my life," Mr. Biden said in October 2020 at a presidential debate.
Ziegler says he only came forward publicly at the request of Congress, adding, "I do this with a heavy heart. This is awful. It's not a fun experience to go through this. I don't wish this upon anyone."
Catherine Herridge is a senior investigative correspondent for CBS News covering national security and intelligence based in Washington, D.C.
Twitter