The Saudi pilot blamed in the killing of three people at a U.S. Navy base in Florida posted criticism of the United States online and quoted slain Al-Qaeda terror leader Osama Bin Laden, a group that tracks extremism says.
A U.S. official on December 7 also told AP that the Saudi hosted a dinner party earlier in the week in which he and three others watched videos of mass shootings.
Federal investigators have not disclosed any motive behind the attack, which occurred on December 6 when the Saudi national is said to have opened fire with a handgun inside a classroom at the Naval Air Station Pensacola.
U.S. Defense Secretary Mark Esper said on December 7 that he was not ready to call it an act of terrorism.
Labeling an act by a Saudi national could be a sensitive topic. Sunni Muslim Saudi Arabia is closely allied with the United States, and Washington relies on Riyadh to be a counter to Shi’ite-led regional rival Iran.
Saudi Arabia's King Salman called President Donald Trump to extend his condolences and pledge his country's support in the investigation.
The Saudi leadership remains under pressure for the killing last year of Washington Post columnist Jamal Khashoggi at the Saudi Consulate in Istanbul. Riyadh blamed that murder on rogue Saudi intelligence officials.
Authorities said a sheriff's deputy who responded to the Florida base fatally shot the gunman after the attack.
Two U.S. officials, speaking on condition of anonymity, named the shooter as Second Lieutenant Mohammed Saeed Alshamrani.
Florida Governor Ron DeSantis said the suspect was attending training at the base as part of a Navy program open to U.S. allies.
One of the three students who attended the reported dinner party videotaped outside the building while the shooting was taking place, a U.S. official told AP on condition of anonymity.
Two other Saudi students watched from a car, the official said. All three are being questioned by investigators.
SITE Intelligence Group, which monitors online Islamist extremism, said Alshamrani appeared to have posted a justification of his planned attack in English on Twitter a few hours before it began.
He referred to U.S. wars in Muslim countries and wrote that he hated Americans for "committing crimes not only against Muslims but also humanity." He also criticized Washington's support for Israel and quoted Bin Laden, SITE said.
Officials said they have so far found no indications Alshamrani had links to international terrorist groups.