Dr. Kevin O’Connor, the former White House physician to Joe Biden, invoked his Fifth Amendment right against self-incrimination during closed-door testimony on 10 July before Republican-led House committees examining whether Biden’s aides concealed signs of cognitive decline while he was in office. Lawmakers overseeing the inquiry said O’Connor’s refusal to answer questions deepens their suspicions of an orchestrated cover-up. Rep. Scott Perry signalled that the panels will call additional witnesses, while Rep. Andy Biggs floated granting O’Connor limited immunity to compel fuller testimony. Rep. Ronny Jackson, himself a former White House doctor, said the move “validates” concerns about Biden’s medical transparency. The investigation gained momentum after Biden’s widely criticised performance in a June 2024 televised debate with Donald Trump, which Republicans cite as evidence of declining capacity. Democratic lawmakers have dismissed the probe as partisan, but have not yet commented on O’Connor’s appearance. No hearing dates for further witnesses have been announced.