Washington (CNN)A suspect who allegedly opened fire on the White House complex Friday afternoon is down and in custody, according to a law enforcement source. The U.S. Park Police said Friday a shooting had occurred in close vicinity to the White House. "Shooting on W. Executive Dr. PIO en route to 17th and Pennsylvania," the law enforcement agency tweeted. Shooting on W. Executive Dr. PIO en route to 17th and Pennsylvania — USPPNEWS (@usparkpolicepio) May 20, 2016 President Barack Obama was not at the White House. Earlier in the afternoon, Secret Service officers cleared the White House North Lawn, Pennsylvania...