Saudi pilot used gun loophole to buy murder weapon used in shooting at Pensacola air base, FBI says

The Saudi military pilot who killed three people in a rampage at a Florida air base while in the United States for flight training obtained the gun he used by taking advantage of a federal gun law exception that allows foreign nationals to legally purchase weapons for hunting, authorities said on Tuesday.

Mohammed Alshamrani, 21, a second lieutenant in the Saudi air force, purchased a Glock 9 mm pistol about four months before authorities said he allegedly opened fire inside a classroom at Air Force Base Pensacola on Friday, killing three U.S. Navy personnel and wounding eight other people before he was gunned down by Escambia County Sheriff's deputies, according to FBI officials.

Prior to the announcement by the FBI Jacksonville field officer, Florida Gov. Ron DeSantis called on the federal government to investigate the federal law that enabled Alshamrani to purchase the gun.

"That's a federal loophole he took advantage of. I'm a big supporter of the Second Amendment -- but the Second Amendment is so that we the American people can keep and bear arms. It does not apply to Saudi Arabians. He had no constitutional right to do that, for sure," DeSantis said at a news conference on Sunday.

Rachel Rojas, special agent in charge of the FBI's Jacksonville field office and the lead investigator on the shooting, previously said Alshamrani "legally and lawfully" purchased the gun.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives website says that under federal law "an alien admitted to the United States under a nonimmigrant visa is prohibited from shipping, transporting, receiving, or possessing a firearm or ammunition unless the alien falls within one of the exceptions."

Under one of the exceptions in the gun laws for "certain official representatives of a foreign government, or a foreign law enforcement officer," Alshamrani was able to obtain a gun after first being granted a Florida hunting license, FBI official said.

"The preliminary investigation into the firearm purchase has not revealed any information to suggest that the sale was unlawful," the FBI Jacksonville field office said in a tweet.

Alshamrani bought the handgun on July 20 at Uber's Lock & Gun shop in Pensacola, a source familiar with the purchase told ABC News.

Naomi Uber, the owner of the gun shop, did not deny the gun was purchased from her business but declined to comment Tuesday when spoken to by ABC News.

ABC News' Josh Margolin, Aaron Katersky and Rachel Katz contributed to this report.