Napolitano responded that Tsarnaev's departure did "ping" in the homeland securityscreeningsystem, but she noted that because the FBI's investigation in 2011 found no suspicious activity, there was no reason to follow up.
New York (CNN) -- In the wake of the failed Christmas Day airplane bombing, President Obama ordered speedy reviews of how the air securitysystem failed and the Transportation Security Administration began enhanced screening for passengers traveling through 14 nations.