The driver of the Tesla Cybertruck that exploded outside the Trump International Hotel in Las Vegas on Wednesday has been identified as Matthew Alan Livelsberger, an active-duty US Army Green Beret, according to a law enforcement source familiar with the investigation.

The 24-year-old said his older brother had increasingly isolated himself from family and friends in the last few years but he hadn’t seen any signs of radicalization when they talked. He said it had been a few months since he had seen his brother in-person and a few weeks since they talked on the phone.