The Saudi airman accused of killing three people at a U.S. Navy base in Pensacola, Florida appeared to have posted criticism of U.S. wars and quoted the late al Qaeda leader Osama bin Laden on social media hours before the shooting.
That's according to SITE Intelligence Group, which tracks Islamist extremism on the internet.
The motive of the attack is not known.
Authorities say the Saudi national was visiting the U.S. for military training, designed to foster links with foreign allies.
He's suspected of firing a handgun inside a classroom at the Naval Air Station on Friday.
A sheriff's deputy fatally shot the gunman, according to authorities.
Among the victims killed was a recent Naval Academy graduate, who according to his family, dreamed of being a fighter pilot.
Within hours - Saudi Arabia's King Salman called President Donald Trump to send his condolences to the victims.
(SOUNDBITE) U.S. PRESIDENT DONALD TRUMP SAYING:
"The King said that the Saudi people are greatly angered by the barbaric actions of the shooter, and that this person in no way shape or form represents the feelings of the Saudi people who love the American people so much.. and I can tell you that was a horrible thing that took place and I can tell you we are getting to the bottom of it."
The incident at the Pensacola base - which employs more than 16,000 military and over 7,000 civilians - happened in the same week a sailor shot three civilians at the Pearl Harbor military base.