Some US Border Patrol agents believe the threat from ISIS on the US border is very real. But some southwestern politicians call the contention little more than anti-Islamic fear-mongering, saying the evidence doesn't support claims of ISIS infiltration.
The al-Qaeda affiliate in Yemen has created bombs that have successfully evaded airport security at least three times. In the security biz, they are known as "artfully concealed devices."
The US-Mexico border is an unforgiving place, where weather can shift quickly from blazing heat to freezing nights. And even those trying to cross into the US illegally will call 911 when they are scared, suffering and need help.