The sniper who killed the conservative activist Charlie Kirk was still on the loose on Friday even as investigators flooded the internet with photos and video of a man believed to have carried out Wednesday's politically charged killing at a Utah university. President Donald Trump said investigators were making progress in tracking down the gunman who fired a single rifle shot on Wednesday that struck the neck of Kirk, a 31-year-old author and podcast host who helped galvanise the conservative youth vote and return Trump to the White House. Officials were still calling the man captured on video a person of interest, not a suspect, but placed him at the scene of the crime at Utah Valley University in Orem,...