WASHINGTON -- One woman was punched in the face as she crested a hill on her bicycle in Northwest Washington. Another was hit in the back of the head as she walked to a bus stop. Neither was robbed, and after one attack, the young men laughed as they made their escape.District of Columbia police say the recent attacks in Washington's Columbia Heights area may be part of a disturbing trend that assailants across the country call the "knockout game." Youths challenge one another to knock out a random person with a single punch.read more