The Saudi gunman who killed three people at the Pensacola naval base had apparently gone on Twitter shortly before the shooting to blast US support of Israel and accuse America of being anti-Muslim, a US official said Sunday as the FBI confirmed it is operating on the assumption the attack was an act of terrorism, the AP reports. Investigators are also trying to establish whether the killer, 2nd Lt. Mohammed Alshamrani, 21, of the Royal Saudi Air Force, acted alone or was part of a larger plot. Alshamrani, who was killed by a sheriff's deputy during the rampage at a classroom building Friday, was undergoing flight training at Pensacola, where members of foreign militaries routinely receive instruction.
"We are, as we do in most active-shooter investigations, work with the presumption that this was an act of terrorism," said Rachel L. Rojas, FBI agent in charge. Authorities believe the gunman made social media posts criticizing the US under a user handle similar to his name, but federal law enforcement officials are investigating whether he authored the words or just posted them, said the official, who was not authorized to discuss the matter publicly and spoke to the AP on condition of anonymity. Also, investigators believe the gunman visited New York City, including Rockefeller Center, days before the shooting and are working to determine the purpose of the trip, the official said. (The killer held a creepy dinner before the attack.)