WASHINGTON — Donald Trump’s signature, an unmistakable if nearly illegible series of bold vertical flourishes, was scrawled on the improper $25,000 check sent from his personal foundation to a political committee supporting Florida Attorney General Pam Bondi.

Charities are barred from engaging in political activities, and the Republican presidential nominee’s campaign has contended for weeks that the 2013 check from the Donald J. Trump Foundation was mistakenly issued following a series of clerical errors. Trump had intended to use personal funds to support Bondi’s re-election, his campaign said.

So, why didn’t Trump catch the purported goof himself when he signed the foundation check?

Trump lawyer Alan Garten offered new details about the transaction to The Associated Press on Thursday, after a copy of the Sept. 9, 2013, check was released by New York Attorney General Eric Schneiderman.

Garten said the billionaire businessman personally signs hundreds of checks a week, and that he simply didn’t catch the error.

“He traditionally signs a lot of checks,” said Garten, who serves as in-house counsel for various business interests at Trump Tower in New York City. “It’s a way for him to monitor and keep control over what’s going on in the company. It’s just his way. ... I’ve personally been in his office numerous times and seen a big stack of checks on his desk for him to sign.”

The 2013 donation to Bondi’s political group has garnered intense scrutiny because her office was at the time fielding media questions about whether she would follow the lead of Schneiderman, who had then filed a lawsuit against Trump University and Trump Institute. Scores of former students say they were scammed by Trump’s namesake get-rich-quick seminars in real estate.

Bondi, whom the AP reported in June personally solicited the $25,000 check from Trump, took no action. Both Bondi and Trump say their conversation had nothing to do with the Trump University litigation, though neither has answered questions about what they did discuss or provided the exact date the conversation occurred.