Gunman al-Shamrani showed a video of the shooting at a party the night before he shot and killed three people at Pensacola base on December 6.

Investigators found video footage at the party when they were investigating whether or not gunman Mohammed al-Shamrani was involved, according to the source. No specific details about the video have been revealed.

A senior official said no terrorist group claimed responsibility and the gunman did not have any clear relationship with international terrorist groups, but some politicians said the attack. should be considered a terrorist act.

"Based on all the evidence I've seen, the US Federal Bureau of Investigation (FBI) will investigate in the direction that this is an international terrorist attack," said MP Michael McCaul, member of the Homeland Security Commission. said that the FBI had informed his staff of the incident.

Al-Shamrani Air Force interns opened fire at Pensacola Naval Air Base in Florida, killing three and injuring eight. The gunman was later shot dead by the police.

"We are looking into what happened, whether it is a person or a group of people. We will quickly find out the truth," US President Donald Trump told reporters on December 7.

SITE Intelligence Group said al-Shamrani posted a short manifesto on Twitter with anti-American content, accusing Washington of financing crimes against Muslims and humanity. Investigators are verifying whether the shooter was the one who wrote the words.

Pensacola Naval Air Base has more than 16,000 soldiers and 7,400 civilian personnel. Saudi King Salman bin Abdulaziz Al Saud phoned US President Trump to offer his condolences, calling the shooting perpetrator "barbarous" and not representing the Saudis.