Joseph Ziegler is a Special Agent / Senior Analyst for the Criminal Investigation division of the IRS having been the primary case agent on the Hunter Biden Investigation. He joined the IRS in 2010 as an IRS-CI special agent having worked a variety of complex tax and money laundering investigations. He also served for a period of time as a Public Information Officer for the Atlanta Field Office serving as a spokesperson for that field office. He was recently selected as a senior advisor to Secretary Scott Bessent at the Department of Treasury. As a senior advisor, he and Gary Shapley are working on reformation plan, which includes Whistleblower related activities, for the IRS.

In 2018 Ziegler was selected to join the IRS-CI’s International Tax and Financial Crime group. Often called the “Seal Team 6 of the IRS”, this elite group of Special Agents investigate high-level tax fraud and financial crimes worldwide. When joining the group, he initiated the tax investigation of Hunter Biden, the son of the Former Vice President, Joseph Biden. While working that investigation, Ziegler through his leadership chain, made protected disclosures for years about misconduct he observed during the investigation. He eventually became a whistleblower and testified in front of the House Oversight Committee and House Ways & Means Committee. After he and his supervisor Gary Shapley made protected disclosures, they both faced significant retaliation from the Department of Justice and the IRS.

Ziegler grew up in Kirtland, Ohio, and graduated from Ohio University in 2007 with a B.S. in Accounting. He worked as an external auditor at Ernst & Young LLP, handling clients like the Cleveland Clinic and Lincoln Electric, while earning his MBA from John Carroll University in 2009.