And then there are Trump’s tax returns. The trove obtained by The New York Times only reveals what Trump told the IRS over the last 20 years, but it does show a variety of dubious accounting techniques to reduce his tax burden. Some of those tactics, such as writing off his personal expenses and potentially paying his elder daughter as a consultant, may invite further scrutiny from IRS investigators and, ultimately, the Justice Department, if it decides to build a case against Trump for violating tax law.

Trump is hardly the only member of his administration whose behavior warrants scrutiny. His eldest son, Donald Trump Jr., has denied allegations that he committed perjury while testifying about the Russia investigation before Congress, as has Commerce Secretary Wilbur Ross, for misleading statements he made about the 2020 census. But as the clock ticks down on his presidency, Trump could issue a wave of preemptive pardons to allies and underlings for any crimes committed during his presidency. In 2018, Trump even asserted that he could pardon himself if he wished—a dubious proposition that would likely have to be resolved by the courts.

Presidential pardons have two major limits: They can’t be used to avoid impeachment, and they only apply to federal crimes. Even Trump can’t immunize himself from charges brought against him by state and local prosecutors. Manhattan District Attorney Cyrus Vance Jr. has spent the last year waging a legal battle in federal courts to obtain Trump’s tax returns and other Trump Organization records, even prevailing in a Supreme Court case this past summer. Vance told the justices that he would not try to indict Trump while he held the presidency. That protective shield expires at noon on January 20, 2021, and criminal charges could follow in New York.