Authorities on Monday continued to investigate a shooting at a Florida naval base that left three people dead and eight wounded as a possible act of terrorism.
A Saudi pilot training at Pensacola's Naval Aviation Schools Command was fatally shot by a sheriff’s deputy during the rampage Friday.
Second Lt. Mohammed Alshamrani, 21, of the Royal Saudi Air Force was the sole shooter, armed with a legally purchased 9mm Glock handgun and several extra magazines, and no arrests have been made in the case, FBI special agent in charge Rachel Rojas said Sunday.
Rojas also said investigators were still trying to determine a motive for Friday's attack.
Here's what we know about the investigation Monday:
Why is the shooting being investigated as an act of terror?
"We work, as we do with most active-shooter investigations, with the presumption that this was an act of terrorism," Rojas said at a Sunday news conference. However, she said the "investigation has not led us to any information that indicated any credible threat to our community."
More on Pensacola shooting: FBI investigating Pensacola rampage as act of terrorism; Saudi student recorded attack
Rojas said investigators were probing whether the shooter acted alone or within a network, or whether "any possible ideology" prompted the attack.
Florida Gov. Ron DeSantis called the shooter somebody with "deep-seated hatred for the United States," who should have been vetted by both the American and Saudi militaries.
Hours before the shooting, tweets purportedly written by the suspect railed against the United States for its support of Israel and for stationing troops at bases in Saudi Arabia. Rojas declined to confirm the tweets came from the Saudi military trainee.
Authorities were tracking a trip that the shooter made to New York with three other students in the days before the attack, a person familiar with the matter said. Based on interviews with those who made the trip, the person said, there is no indication so far that the travel was linked to anything sinister.
The trip lasted about four days. “They did touristy things,” said the person, who is not authorized to speak publicly.
After the group returned to Florida, the person said, the shooter and others at a dinner gathering watched videos related to mass shootings.
Rojas declined to comment on the trip and the dinner party.
The Associated Press also reported one of the three students who attended the dinner later recorded video outside the building while the shooting was taking place. Two other Saudi students watched from a car, AP reported, citing a U.S. official who spoke on condition of anonymity after being briefed by federal authorities.
The New York Times, citing a person briefed on the investigation, said the student who recorded the video later told investigators he just happened to be in the area when the shooting broke out. The FBI said in a statement that it had obtained video taken by a bystander from outside the building after the attack had begun and after first responders had arrived.
How did the gunman have access to a firearm?
The pistol used in the shooting was purchased "legally and lawfully" in Florida through a process that was open to "any foreign national," Rojas said.
"That’s a federal loophole that he took advantage of," said DeSantis, adding that he would urge President Donald Trump and other federal decision-makers to change policies that allow foreign nationals to arm themselves.
DeSantis says to end 'loophole': Florida Gov. calls for gun restrictions after deadly Pensacola rampage
Under U.S. code, foreign nationals who have been lawfully admitted to the U.S. can purchase and possess a gun under a few specific conditions:
If they were admitted to the U.S. for lawful hunting or sporting purposes or if they are in possession of a U.S.-issued hunting license or permit
If they are an official representative of a foreign government who is accredited with the U.S. government; if they are accredited with a government-partnered international organization headquartered in the U.S.; or if they are in transit to or from a country where they are accredited
If they are an official of a foreign government or a distinguished foreign visitor as designated by the U.S. Department of State
If they are a foreign law enforcement officer of a friendly foreign government entering the U.S. on official law enforcement business
There is also a process where a foreign national can petition the U.S attorney general directly for a waiver that allows them to possess a gun.
It is unclear exactly what criteria allowed the Pensacola gunman to purchase a firearm, but he was a member of the Royal Saudi Air Force who was credentialed with the U.S. through an aviation training program.
However, Acting Defense Secretary Mark Esper said he had ordered a review of the Defense Department's security and vetting policies. Guns are not allowed on the base, said Navy Rear Adm. Gary Mayes, without prior approval.
Why was the gunman training in the United States?
Alshamrani was one of 852 Saudi nationals in the United States training under a cooperation agreement. He was among 5,180 foreign students from 153 countries in the United States for military training. Many of those students operate U.S. military hardware that foreign governments buy from the United States.
Training international students at Navy Air Station Pensacola is a core part of the base's mission.
The shooter began his three-year course in August 2017 with English, basic aviation and initial pilot training, said officials, who were not authorized to speak publicly because of the ongoing investigation.
Foreign military trainees are vetted before traveling to the United States. U.S. Embassy personnel research databases for activities such as support for terrorism, drug trafficking, corruption and other criminal behavior. Travel orders are denied to those who fail to pass the screening, one official said.
US-Saudi alliance: Pensacola shooting by Saudi national raises new questions
The shootings in Florida come at an already tense moment in U.S.-Saudi relations after Saudi Arabia's role in the 2018 slaying of Jamal Khashoggi, a U.S. resident and Washington Post journalist.
Secretary of State Mike Pompeo said Saturday that he spoke with Saudi Arabia's foreign minister, "who expressed his condolences and sadness at the loss of life in the horrific attack" in Florida.
Who are the victims?
The Navy identified the victims as Airman Mohammed Haitham, 19, of St. Petersburg, Florida; Ensign Joshua Kaleb Watson, 23, of Coffee, Alabama; and Airman Apprentice Cameron Scott Walters, 21, of Richmond Hill, Georgia.
Watson "saved countless lives," his family said after the shooting.
“Heavily wounded, he made his way out to flag down first responders and gave an accurate description of the shooter,” his father, Benjamin Watson, said. “He died serving his country.”
Contributing: Dennis Wagner, Annie Blanks, Tom Vanden Brook, Kevin Robinson, John Bacon and Deirdre Shesgreen
This article originally appeared on USA TODAY: Pensacola shooting update: NAS Pensacola being investigated as terror