They said he had also traveled to both Egypt and Canada in the two years prior, though it was unclear what he did on those trips.
US Army veteran Shamsud-Din Jabbar first came to the Louisiana city from his Texas home in late October, the Federal Bureau of Investigation said in a briefing.
On that first visit, according to a video released by the agency, Jabbar slowly rode a bicycle through the iconic French Quarter while filming the scene with his Meta smart glasses.
Meta glasses allow users to take photos or videos without using their hands, FBI special agent Lyonel Myrthil said.
The video shows Jabbar at one point studying his reflection in a full-length mirror, possibly testing the glasses.
He visited the city again on November 10, according to the FBI.
Myrthil said Jabbar was wearing the glasses, but did not activate them, before dawn on New Year's Day when he conducted his attack in the heart of an iconic American nightlife district.
Police say he drove a rented pickup truck around a barrier and down busy Bourbon Street at high speed -- killing 14 people and injuring at least 30 -- before dying in a shootout with police.
Jabbar -- a US citizen who on social media had declared his allegiance to the Islamic State militant group -- had traveled abroad twice in the past two years, according to the FBI.
Myrthil said Jabbar visited Cairo for 11 days in the summer of 2023 and the Canadian province of Ontario for three days around a week later. The FBI said it was trying to find anyone he might have met on those trips.
The FBI said two firearms had been recovered during their investigation: a 9mm pistol and a .308-caliber semi-automatic rifle.
They added that if New Orleans police had not responded as quickly as they did, Jabbar could have detonated two homemade bombs he had left along his path.
