afghanistan. officials telling cnn that farook was in the social circle of one of the men. a recruiter serving 25 years in prison. there is information about the guns used in the attacks. federal sources telling cnn that syed rizwan farook asked his neighbor marquez, because he feared he would not pass a background checks. the ar-15s were bought in 2011 and 2012 at the time marquez and farook were considering a different attack. more on the investigation with cnn's kyung lah in san bernardino. >> reporter: alison and christine, fbi dive teams have been painstakingly searching this lake bit by bit. there is a report that the two killers were spotted here at this park on the day of the massacre. the fbi not specifying whether that report was before or after the massacre, but they say they