The family of U.S. Capitol Police Officer Brian Sicknick, who lost his life defending the U.S. Capitol on Jan. 6, 2021, told attendees of the Democratic National Convention Thursday they hold Donald Trump responsible. Sicknick’s brother Craig and mother Gladys stood side by side on the stage of the United Center in Chicago as a monitor on stage showed a photograph of the smiling cop who died one day after he was attacked by Capitol rioters. “My brother was a Capitol police officer, Brian Sicknick, a hero who died after defending the country on Jan. 6,” he said. Want more breaking political new…