The gunman who opened fire at a U.S. Immigration and Customs Enforcement facility in Dallas, Texas, sought “real terror” for agents and “searched apps that tracked the presence” of ICE personnel, FBI Director Kash Patel revealed Thursday.

Joshua Jahn, 29, was identified by sources familiar with the investigation as the shooter who opened fire from a rooftop toward the ICE facility, killing one detainee and injuring two others. The shooter died after turning the gun on himself, authorities said.

Joshua Jahn allegedly shot up an ICE facility in Dallas, Texas, on Wednesday and a bullet with “ANTI-ICE” on it was found at the scene. (FBI; Contributed to Fox News)

Patel also said that the gunman searched for videos of Charlie Kirk’s assassination in Utah leading up to the attack in Dallas on Wednesday. 

This is a developing story. Please check back for updates. 

Fox News’ Louis Casiano and John Roberts contributed to this report.