A Pakistani immigrant suspected of stabbing two people outside the former offices of the Charlie Hebdo magazine in Paris followed a South Asian Islamic sect that in Pakistan has become increasingly emboldened, and on occasion sparked violence, in defending the central figure in Islam from what adherents see as blasphemous insults.
In a video police say they found on the suspect’s phone and that was released on social media after the attack, a man who says he plans to stage an attack on Friday—when the stabbing occurred—appears…