Charlie Hebdo Shooting: Homegrown, 'Lone Wolf' Terrorism Raises Security Concerns In Europe

European nations are tightening security at borders and vulnerable areas this week after purported Islamic extremists carried out a shooting Wednesday that left 12 people dead outside French satirical magazine Charlie Hebdo's headquarters in Paris. Leaders stressed the enhanced measures were precautionary attempts at due diligence, given the fact that two of three suspects in the attack remained at large Thursday.