Charlie Hebdo attack: What we know and don’t know

Blasts and gunshots were heard from both locations Friday afternoon. Twelve people were killed in Wednesday’s attack on Charlie Hebdo in Paris, which has prompted widespread shock and condemnation. Separately,…

When is your tweet a threat?

Police reviewed hundreds of online postings–and made several arrests–over alleged anti-cop threats made in the wake of the killing of two officers last month. It used to be a lot…