The FBI has found mobile phone evidence linking Al Qaeda to a shooting at a US naval base in which three people were killed, the New York Times reported on Monday.
The newspaper cited officials briefed on the investigation into the attack, which occurred in Pensacola, Florida, on December 6 last year.
In February, an audio recording purported to be from the extremist group Al Qaeda in the Arabian Peninsula claimed responsibility for the shooting, but provided no evidence.
The shooter, Second Lieutenant Mohammed Saeed Alshamrani, 21, was a member of the Royal Saudi Air Force.
He was on the base as part of a US Navy training programme designed to foster links with allies. He was killed by police during the attack.
The US Justice Department has been trying to unlock the encryption on Alshamrani’s phone to ascertain his motives and whether he had connections to known terrorist groups.
Before the shooting spree, Alshamrani posted criticism of US wars and quoted Al Qaeda leader Osama bin Laden on social media.
After a review, the US military said in December that Saudi Arabian military students in the United States, said to number about 850, presented no threat.
“We can report that no information indicating an immediate threat scenario was discovered,” said Garry Reid, a director for defence intelligence, counterintelligence, law enforcement and security, briefing Pentagon reporters.
The conclusion cleared the way for the US military services to, at their discretion, lift a freeze on operational training that had grounded Saudi military pilots and restricted Saudi air crews and infantry officers to classwork.
The attack was widely condemned in the kingdom and US President Donald Trump said King Salman had reached out to him personally to express his own condolences.
Saudi Minister of State for Foreign Affairs Adel Al Jubeir also tweeted his sympathies.
King Salman told Mr Trump that “the perpetrator of this heinous crime does not represent the Saudi people, who count the American people as friends and allies”, a statement released by the Saudi Arabian embassy in Washington said.
Saudi officials also visited the air force base to meet their US counterparts.
