Axel Rudakubana, 17, pleaded guilty to three counts of murder and 10 counts of attempted murder after a stabbing at a Taylor Swift-themed dance class in Southport, England. He also admitted to possessing terrorist material and producing ricin. Rudakubana will serve a life sentence. The attack killed three children and injured 10 others. Taylor Swift expressed shock and sympathy for the victims and their families on Instagram.