Donald Trump will appear in a New York courtroom on Monday, becoming the first former US president to face a criminal trial.
He is accused of falsifying his business records to conceal a hush-money payment made to Stormy Daniels, a former adult film star, just before the 2016 election.
Mr Trump, 77, faces up to four years in prison if convicted, but he could avoid jail and instead be fined. He's pleaded not guilty.
Mr Trump's historic trial will take place against the backdrop of his presidential campaign, with the possibility that the presumptive Republican nominee will be convicted of a felony months before the November election.
The trial, which begins with jury selection on Monday, is expected to last six to eight weeks and will focus on Mr Trump's reimbursement to his former fixer Michael Cohen.
Cohen, 57, claims he was directed to pay Ms Daniels $130,000 (£104,000) in exchange for her silence regarding an alleged affair with Mr Trump.
Hush money payments are not illegal. However, the Manhattan District Attorney's Office claims that Mr Trump committed a crime by improperly recording the reimbursement to Cohen as legal expenses.
He is charged with 34 felony counts of falsifying business records in the first degree. To reach a decision, all 12 jurors must agree on whether Mr. Trump is guilty or not guilty of a specific charge.
The trial in Manhattan is expected to feature testimony from a colorful cast of characters central to the case, including Cohen, Ms Daniels, and Mr Trump's personal lawyer, who was imprisoned in part because of the scandal.
Experts are divided on the prosecution's case, which takes a novel approach to bringing felony charges for falsifying business records.
Mr Trump has made several attempts to postpone the jury trial and relocate it from Manhattan, which is predominantly Democratic.
His fiery remarks about the case, which he has repeatedly described as politically motivated, prompted the judge to issue a gag order prohibiting him from making public comments about people involved in the case, including witnesses.