U.S. Capitol Police officer Brian Sicknick died of injuries suffered when supporters of President Donald Trump assaulted the legislative building, the force said on Thursday, bringing to five the number dead from the riot.
Wednesday's breach of the U.S. Capitol building was a stunning assault on American democracy when lawmakers were in the building certifying the victory of President-elect Joe Biden.
"Officer Sicknick was responding to the riots...and was injured while physically engaging with protesters," police said in a late-night statement.
He succumbed on Thursday after being taken to hospital following his collapse upon returning to his divisional office, they added.
Metropolitan homicide officials will investigate the death of Sicknick, who joined the U.S. Capitol Police in 2008, along with the Capitol force and its federal partners, police said.