People across America are mourning the death of capitol police officer William Evans

Mr Evans died after 25-year-old Noah Green rammed a car into a barricade at the US Capitol, and launched a knife-wielding assault at Police.

Flags are being flown at half mast at the White House and the Capitol, to show respect to the fallen officer.

CNN reports it's another blow to US authorities.

Mr Evans was an 18-year veteran of the force, and is the second Capitol police officer to die in just three months.

Speaker of the House Nancy Pelosi described the officer as a martyr for democracy.