STORY: Former National Enquirer publisher David Pecker, the first witness in Donald Trump's New York hush money trial, ended his testimony on Friday in the first criminal trial of a former president in U.S. history.

Pecker on Friday said he suppressed a story about an alleged affair to help Trump's 2016 presidential bid even though it would have boosted sales of his tabloid.

The prosecutor asked him if he "killed the story because it helped the candidate, Donald Trump?"

Pecker said yes.

The exchange bolstered previous testimony in which Pecker said he worked with Trump's campaign to suppress allegations of adultery at a time when he was facing multiple accusations of sexual misbehavior.

Trump is charged with falsifying business records to cover up a hush money payment to porn star Stormy Daniels.

Pecker testified that his tabloid paid to "catch and kill" embarrassing stories about Trump and alerted the then-candidate that Daniels was looking to sell her story of a sexual encounter with Trump.

The defense has argued the hush money payment was made to spare Trump's family embarrassment, not bolster his campaign.

Trump denies an encounter took place and has pleaded not guilty to the charges.

Under cross-examination, a lawyer for Trump sought to undermine Pecker's credibility.

The defense attorney asked Pecker whether he had inaccurately testified that Trump thanked him at the White House for handling those negative stories.

That conflicted with a report by FBI agents who previously interviewed Pecker, which said Trump had not expressed gratitude. Pecker said the FBI report could be wrong.

Trump's lawyers also sought to illustrate that Pecker's checkbook journalism was not confined to Trump.

Under questioning on Thursday, Pecker said the Enquirer paid hundreds of thousands of dollars to obtain stories from women who came forward during Arnold Schwarzenegger's 2003 run for California governor to say they had affairs with him.

The trial resumes Monday.