By Jan Wolfe WASHINGTON (Reuters) -A federal prosecutor accused a Texas man of being “a leader” of the Jan. 6, 2021, assault on the U.S. Capitol by Donald Trump supporters as she wrapped up arguments on Monday in the first criminal trial of someone accused of joining the riot. Guy Reffitt of Texas, is the first of some 750 people charged with joining in the riot to face trial in Washington. “Every mob needs leaders, and this defendant was a leader that day,” Justice Department lawyer Risa Berkower told jurors. “When the defendant stepped to the front of the crowd, he forced the Capitol Police …