The Dec. 6 mass shooting at Naval Air Station Pensacola was ’an act of terrorism,’ U.S. Attorney Bill Barr said at a Monday news conference. Barr also announced that 21 Saudi military students have been sent back to their home country. In the meantime, the FBI is continuing to work on new leads in the case.

WASHINGTON, D.C. — The Dec. 6 mass shooting at Naval Air Station Pensacola by a Saudi aviation student “was an act of terrorism ... motivated by jihadist ideology,” U.S. Attorney General Bill Barr said Monday.

But, Barr added, the ongoing FBI investigation into the shooting has not produced any evidence that the NAS Pensacola incident is part of any more widespread plans for terrorist attacks in this country.

The United States has had a long practice of training Saudi military personnel in this country, although the Dec. 6 shooting has prompted a serious look at how those students, and other foreign military students, are vetted for entry into this country.

Barr said Monday that vetting “should be improved,” but added that even that might not have prevented the Dec. 6 mass shooting.

Saudi pilot Mohammed Alshamrani, 21, killed three people and injured eight others on the morning of Dec. 6 in a classroom building at NAS Pensacola before he was fatally shot by an Escambia County sheriff’s deputy. As a result of the FBI probe, 21 Saudi military students in the United States were being sent back to their home country on Monday, Barr announced.

The terrorist attack at NAS Pensacola struck the heartbeat of our community but failed to shake our unwavering patriotism and support for our military.

As we heal, we must never forget those who lost their lives in one final demonstration of love for our country and for freedom. pic.twitter.com/CMadm88xmY

— Rep. Matt Gaetz (@RepMattGaetz) January 13, 2020

There is no evidence that any of the 21 students had aided Alshamrani in any way. However, Barr noted, the 21 Saudi military personnel were in possession of what he called “derogarory materials.” Of those 21 students, Barr said, 17 were found in possession of materials containing jihadist or anti-American sentiments.

In addition, 15 of the students, including some of the 17 who were in possession of anti-American materials, had some contact with child pornography.

But, Barr noted, in no case would the information developed with regard to any of the 21 students have resulted in successful federal prosecution.

PHOTOS: NAS Pensacola shooting

Barr said the Saudi government has ensured U.S. officials that they will provide full access to the 21 students, and will return them to the United States for trial, should that become necessary.

Also, Barr said, the Saudi government has directed its military students to cooperate fully with American authorities in the ongoing investigation.

With regard to Alshamrani, Barr said that in September, a post on social media by Alshamrani read, “the countdown has begun.” On Sept. 11, Alshamrani was in New York City, where he visited the 9/11 memorial, Barr said.

Barr also countered rumors that Saudi students outside the classroom building who captured video footage of the Dec. 6 incident were involved in the attack.

Those students fully cooperated with the investigation, as did all of the other Saudi military students at NAS Pensacola, according to Barr.

Barr and FBI Deputy Director David Bowdich used much of Monday’s news conference to pressure technology company Apple to “unlock” Alshamrani’s two iPhones to allow authorities to determine whether they contain information pertinent to the investigation of the NAS Pensacola shooting.

Barr would not say Monday whether the Department of Justice would go to court to get Alshamrani’s phones unlocked.

Bowdich told reporters that the investigation has been proceeding around the clock since Dec. 6 to determine whether Alshamrani acted alone or had some assistance. More than 500 witnesses have been interviewed, he said, and the FBI is continuing to check out new leads in the case.

Providing a detailed rundown of the Dec. 6 events at NAS Pensacola, Bowdich said the incident lasted 15 minutes, and that Alshamrani was first engaged by naval security forces eight minutes after the attack began.

Alshamrani was armed with a semiautomatic handgun, magazines and 180 rounds of ammunition. The gun was lawfully purchased under a “hunting license exception” in Florida law that allows non-immigrant visa holders to purchase a weapon if they have a valid state-issued hunting license.

Shortly after the new conference, Rep. Matt Gaetz, R-Fla., whose district includes NAS Pensacola, posted the following statement on Twitter: “The terrorist attack at NAS Pensacola struck the heartbeat of our community but failed to shake our unwavering patriotism and support for our military.

“As we heal,” Gaetz continued, “we must never forget those who lost their lives in one final demonstration of love for our country and for freedom.”

The day after the shooting, the Daily News filed Freedom of Information Act (FOIA) requests with the Navy, the Naval Criminal Investigative Service and the Department of Defense seeking information on Alshamrani and any other Saudi personnel studying at NAS Pensacola on that date.

Both the Navy and the NCIS rejected those requests for information, citing the ongoing investigation

The FOIA request to the DoD remains outstanding. In a Dec. 20 letter to the newspaper, the DoD’s U.S. Central Command, whose area of responsibility includes Saudi Arabia, stated in part that “the processing time for these documents will depend upon consultation with other DoD components, stateside, overseas, or other agencies.”