Hur told the House Judiciary Committee that the evaluation was fundamental to his investigation into whether the president intentionally hoarded classified documents during his time out of office.

“My task was to determine whether the president retained or disclosed national defence information willfully — meaning knowingly and with the intent to do something the law forbids,” Hur told the committee. “For that reason, I had to consider the president’s memory and overall mental state.”

Questions about Biden’s memory arose after Hur released a special report in February that described the president fumbling to recall details, including dates surrounding his son Beau’s death.

In the report, Hur wrote that Biden, 81, would present to a jury “as a sympathetic, well-meaning, elderly man with a poor memory”. He did not recommend pressing charges.

Nevertheless, his conclusions elicited criticism from both Democrats and Republicans.

Democrats have accused the investigator of gratuitously referencing Biden’s age — which has become a charged election issue in 2024, as voters question whether he is fit for a second term.

Republicans, meanwhile, seized on Hur’s report to suggest Biden was getting preferential treatment compared with former President Donald Trump, who has been indicted on charges related to retaining classified documents.

Hur, a registered Republican, addressed the controversy in his testimony on Tuesday. “My assessment in the report about the relevance of the president’s memory was necessary and accurate and fair,” Hur told legislators. “I did not sanitise my explanation, nor did I disparage the president unfairly.”

Pushback on Capitol Hill

But top members of both parties in the House pushed back against Hur’s assessment on Tuesday.

“You cannot tell me you’re so naive as to think your words would not have created a political firestorm,” Representative Adam Schiff, a Democrat, said during the hearing, criticising Hur’s repeated invocation of Biden’s age.

“You were not born yesterday. You understood exactly what you were doing,” Schiff continued. “It was a choice. You certainly didn’t have to include that language.”

Also during the hearing, Representative Matt Gaetz and other members of the Republican Party accused Hur of using Biden’s memory as an excuse not to prosecute him.

They also sought to portray Hur’s assessment of Biden as part of a long-running double standard that targeted Trump unfairly.

In February’s report, Hur distinguished between Biden’s handling of classified documents and Trump’s, noting differences in the number of documents withheld and how they were returned.

“After being given multiple chances to return classified documents and avoid prosecution, Mr Trump allegedly did the opposite,” Hur pointed out. But Gaetz revisited that point in Tuesday’s hearing.

“Biden and Trump should have been treated equally,” Gaetz said. “They weren’t. And that is the double standard that I think a lot of Americans are concerned about.”

Trump also weighed in on the hearing. “The DOJ [Department of Justice] gave Biden, and virtually every other person and President, a free pass,” he posted on social media. “Me, I’m still fighting!!!”

For his part, Hur told legislators that “partisan politics had no place whatsoever in my work.”

More balanced view

Still, transcripts of the interviews Hur and his team had with Biden offer a more nuanced look at what happened, calling into question both Hur’s and Biden’s characterisations of how the events played out.

The partially redacted transcripts were released on Tuesday, before Hur’s scheduled appearance before the House committee.

They renewed scrutiny over one of the most high-profile descriptions in Hur’s original report: depicting Biden’s apparent confusion about the date of his son Beau’s death.

Hur used the instance as an example of the president’s alleged memory lapses. But Biden quickly condemned Hur for mischaracterising him, holding an impromptu press conference in February to express his outrage.

“How the hell dare he raise that?” Biden said at the time. “Frankly, when I was asked the question, I thought to myself it wasn’t any of their damn business.”

Tuesday’s transcripts show that Hur never directly asked Biden about his son. They also suggest Biden’s memory lapse was perhaps less significant than Hur detailed in the report.

The investigator present at the time asked Biden about where he kept the things that he was “actively working on” while he was living in a rental home in Virginia immediately after leaving the vice presidency in January 2017.

In that context, Biden brought up Beau’s illness and death as he talked about a book he had published later in 2017 about that period in his life.

“What month did Beau die?” Biden said aloud, adding, “Oh God, May 30th.”

A White House lawyer chimed in with the year, 2015.

“Was it 2015 he died?” Biden asked again.

He went on to recount in detail a story contained in the book — entitled Promise Me, Dad — about how his late son had encouraged him to remain engaged in public life after his vice presidency ended.