On Wednesday, British Home Secretary Amber Rudd said that Salman Abedi, the 22-year-old man who is believed to have exploded a suicide bomb at an Ariana Grande concert on Monday night, was known to British intelligence and security agencies "up to a point." The bombing, which killed 22 people, including children, and wounded dozens of others, "was more sophisticated than some of the attacks we've seen before, and it seems likely — possible — that he wasn't doing this on his own," she added.