MIAMI — The U.S. Customs and Border Protection agent killed at a West Miami-Dade gun range on Wednesday was accidentally shot by a fellow agent, Miami-Dade police said on Thursday. Multiple law enforcement sources told the Miami Herald that it happened during a role-playing scenario in which one of them was trying to subdue a bad guy. The sources said the agent who shot Arias had accidentally replaced his training pistol with his handgun, which carried live ammunition. How that happened wasn’t immediately clear. The Miami Herald identified the agent killed as Jorge Arias, 40, a nine-year veter…
