The number of migrants caught illegally crossing the U.S.-Mexico border dropped on Friday, a senior U.S. border official told Reuters, saying it signaled a restrictive new Biden administration policy was deterring some illegal immigration. U.S. Border Patrol arrested around 3,100 people crossing illegally, down roughly 20% from the days before, the official said, requesting anonymity to discuss preliminary figures. "It's still too early to say this is a definitive trend," the official...