New details have emerged about the fatal shooting at a Dallas Immigration and Customs Enforcement (ICE) facility on Wednesday, where a sniper opened fire, killing one detainee and injuring two others. The suspect, identified as Joshua Jahn, left behind a handwritten note expressing intent to instill fear in ICE agents.

FBI Director Kash Patel revealed that the note stated, “Hopefully this will give ICE agents real terror, to think, ‘is there a sniper with AP rounds on that roof?’” referring to armor-piercing bullets. Patel highlighted that Jahn, 29, had conducted extensive research prior to the attack, including searches for apps tracking ICE agents and downloading a document titled “Dallas County Office of Homeland Security & Emergency Management,” which lists Department of Homeland Security (DHS) facilities.

Additional evidence suggests Jahn engaged in pre-attack planning, conducting multiple searches on ballistics and a video titled “Charlie Kirk Shot Video” between September 23–24. Between August 19–24, he also searched apps designed to monitor ICE agent locations. Jahn died from a self-inflicted gunshot wound after the incident.

FBI Dallas and FBI Headquarters are continuing investigations, analyzing devices, data, and writings recovered from the scene and Jahn’s residence. The bureau has emphasized its commitment to providing updates as information becomes available.