Rita says that the ex-wife got a restraining order on him in Tacoma citing violence. The Chevy Caprice - Burgundy - belongs to his New Jersey girlfriend. Her house is a block and a half from a train station.
Training, equipment, procedure knowledge, ability to blend in afterwards, veil of innocence, DC cop hiring practices,....
Could be Muslim too. Church helping him with a rental car fleet and providing vehicular support and confusion with similar looking cars.