Federal investigators are trying to determine what caused a U.S. Army veteran to snap and bring terror to the streets of New Orleans.

Teams of federal agents have been scouring every location tied to 42-year-old Shamsud-Dun Jabbar for more than 24 hours now. Jabbar, a Texas native who served more than a decade in the Army, Reportedly recorded a series of videos in which he said he wanted to kill his family and join Isis in the hours before he sped onto busy Bourbon Street with a rented pickup truck.

He reportedly used the truck to mow down dozens of people during New Year's Eve celebrations in the French Quarter, killing 15 people. He was eventually killed in a shootout with police.

RELATED STORY | Biden says New Orleans attacker posted about being inspired by ISIS

Officials are concerned that Jabbar did not act alone as law enforcement beefs up security. The Sugar Bowl, which was scheduled for Wednesday evening, was postponed to Thursday, giving officials one extra day to bolster security.

President Joe Biden said Wednesday that the investigation was in the "preliminary stage."

"The law enforcement intelligence community will continue to look for any connections, associations, or co-conspirators," he said.

Meanwhile, some of the victims killed in the attack have been identified. Among them, Reggie Hunter, a Baton Rouge father. Also Tiger Bech, a former college football player for Princeton.

RELATED STORY | Sugar Bowl postponed to Thursday following deadly attack in New Orleans