The Trump administration plans to temporarily reassign 120 F.B.I. agents in Washington to nighttime patrol duties as part of President Trump’s crackdown on the city’s street crime, according to people familiar with the matter. Most of the agents will be pulled from their regular duties at the F.B.I.’s Washington field office, but it was not immediately clear if agency leaders would need to pull additional personnel from nearby cities, the people said, speaking on condition of anonymity to...