Shamsud-Din Jabbar, a US Army veteran who is suspected of being behind the New Orleans terror attack that resulted in 15 deaths, was “100% inspired” by Islamic State (IS, formerly ISIS), the FBI confirmed on Thursday. He supposedly recorded a series of videos in which he pledged allegiance to the group, CNN reported on the same day, citing multiple officials.

The FBI is now digging deeper into the suspect’s radicalization path, a deputy assistant director of the bureau’s counterterrorism division, Christopher Raia, told a news conference on Thursday morning. He also said that investigators believe Jabbar acted alone.

“We do not assess at this point that anyone else is involved in this attack other than Shamsud-Din Jabbar,” Raia said. US President Joe Biden had said that federal investigators were examining a “possible connection” between the New Orleans attack and an explosion of a Tesla Cybertruck in Las Vegas that took place on Wednesday.