US lawmakers launch probe into New Year’s Day attacks

US Republican lawmakers launched an investigation Thursday into deadly New Year's Day attacks in New Orleans and Las Vegas.

Senators Chuck Grassley and Ron Johnson sent letters to the FBI and departments of Justice, Homeland Security and Defense to demand further information on the backgrounds and motives of the ISIS-inspired New Orleans attacker Shamsud-Din Jabbar and Las Vegas perpetrator Matthew Alan Livelsberger.

"The public deserves complete transparency and the truth regarding the New Orleans terrorist attack and the Las Vegas car explosion," Grassley and Johnson wrote.

"While we understand the investigation into both of these incidents is ongoing, we expect your agencies to be forthcoming and responsive to oversight requests from Congress on this very serious matter," they added.

At least 14 people were killed and dozens injured in New Orleans when Jabbar, a US Army veteran, drove a pickup truck into a crowd of revelers in the French Quarter on Bourbon Street.

Livelsberger, an active duty member of the Army Special Forces, shot himself in the head in a Tesla Cybertruck packed with firework mortars shortly before it exploded outside the Trump International Hotel in Las Vegas.