WASHINGTON — John Yoo, a law professor at the University of California, Berkeley, confirmed on Monday, June 29, 2026, that he would advise a team of prosecutors investigating whether former law enforcement and intelligence officials conspired against President Donald Trump. Yoo stated he would be assisting Joe diGenova, a former Justice Department prosecutor.

DiGenova was assigned in April 2026 to investigate whether officials participated in a criminal conspiracy against President Trump. The investigation is being conducted in Florida.

Prosecutors have centered at least part of the probe on the investigation into Russian interference in the 2016 U.S. presidential election. Investigators have issued subpoenas for records and conducted interviews related to the creation of an intelligence community assessment released in January 2017.

The assessment found that Russia engaged in wide-ranging election interference to boost Donald Trump over Hillary Clinton. A 2019 report by special counsel Robert Mueller affirmed that Russia interfered in the election on Trump's behalf and that the Trump campaign repeatedly welcomed Russian assistance. The report did not find sufficient evidence to establish a criminal conspiracy between Moscow and the Trump campaign.

Regarding Yoo's role, diGenova said, "He's a lawyer. He's going to be helping us." Todd Blanche, acting Attorney General, stated, "That's exactly what we're investigating right now."

Several subsequent investigations into the Russia probe identified multiple errors in how it was conducted. One former FBI lawyer pleaded guilty in 2020 to doctoring an email during the course of the Russia inquiry. Reviews of the probe have not identified criminal misconduct by any senior law enforcement or intelligence official involved in the investigation.

Yoo previously served as a senior Justice Department official in the George W. Bush administration. He was a lead author of memos government officials used to justify using enhanced interrogation techniques on potential terror suspects after the Sept. 11, 2001, terror attacks. The Justice Department later rescinded the memos authored by Yoo. In a 2020 interview, Yoo stated that he had told Trump administration officials multiple times that a Supreme Court ruling which rejected Trump's effort to end the Deferred Action for Childhood Arrivals program opened the door to enormous new presidential power.