A Columbia University doctoral student was knifed to death Thursday night near the Ivy League college's historic Manhattan campus - one of three people attacked by an 'ecstatic' gang member on a violent stabbing spree. Davide Giri, 30, a PhD candidate in computer science, died around 11pm after being stabbed in the stomach by a 25-year-old member of the Bloods gang off-shoot, Everybody Killas, who has 16 prior arrests dating back to 2012 and was out on parole for a 2015 gang assault, police said. Officers arrested the suspect - Vincent Pinkney, of Manhattan- in Central Park 20 minutes later,...