A Boston parking valet armed with an umbrella managed to fight off a knife-wielding purse snatcher. Police report 23-year-old valet Felix Vega came to the aid of a 61-year-old woman. A man had jumped into her car and threatened her with a knife. Police say Vega grabbed an umbrella and started whacking the crook, who ran off. Police arrested Richard Morse nearby. Officers say he still had the victim's purse.