Authorities say the suspect accused in the deadly New Year's Day truck attack in New Orleans that killed 14 people visited the city twice in the months leading up to the attack and may have used special hands-free glasses to record the city's historic French Quarter.

Speaking at a press conference Sunday afternoon, FBI Assistant Director Christopher Raia said Shamsud-Din Jabbar, a U.S. citizen and Army veteran from Houston, also traveled abroad to Egypt, Cairo and Canada prior to the attack.

Investigators are still looking at what correspondence — if any — Jabbar may have had with others while out of the country, but authorities said there are currently no indications of any other suspects involved in the attack.

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Jabbar, 42, was ultimately killed during a gunfight with police after driving a rented pickup truck into a crowd of New Year's revelers around 3 a.m. local time in the historic area of Bourbon and Canal Street.

The FBI said two guns, an ISIS flag, and a potential improvised explosive device were located inside the vehicle. Authorities added that other potential IEDs were also located in the French Quarter, though none were detonated.

In addition to the 14 victims killed, dozens of others remain hospitalized with injuries. Louisiana Gov. Jeff Landry announced Sunday that he was issuing an executive order for a dedicated period of mourning, in which flags will be flown at half-staff and each victim will receive their own day of remembrance, beginning Monday.

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Authorities reiterated that this is a fluid investigation that stretches across state and international borders, but that each day the picture becomes clearer as they examine new evidence.

President Joe Biden is slated to visit New Orleans on Monday to pay his respects to the victims and their families and offer full federal help and support to those in need in the surrounding community.