16-year-old fatally shot at Brookland Metro station in Washington D.C. on Apr 4; suspect sought.

16-year-old fatally shot at Brookland Metro station in Northeast Washington D.C. on Apr 4; D.C. police search for male suspect with black jacket, light blue jeans, and gray backpack; Red Line trains bypass the station during investigation; Catholic University nearby issues "Shelter in Place" order.