>>e are hearing from sources they don't believe there is another suspect in this shooting. they believe there is a single gunman, that there was cop fusion at the scene and people may have thought they saw other people with guns responding to the scene. they may have thought they were involved in the shooting. that's not confirmed. we do have a news conference we expect to begin any minute now. i have been told ten minutes from now it will include d.c. mayor anthony gray, chief of police in d.c. and the head of the d.c. office of the fbi which is heading the the investigation. the shooter was identified as aaron alexis. he was in the navy. he was kicked out back in 2011 after being arrested on a gun charge in 2010 in ft. worth, texas. we know there are 13 dead including the shooter. there were many, many rounds in