() The suspected shooter involved in Wednesday’s deadly targeted attack at the Dallas ICE Field office conducted multiple searches of the deadly shooting of conservative activist Charlie Kirk, the FBI announced on Thursday.

Joshua Jahn, 29, was identified as the person linked to Wednesday’s deadly shooting, which killed one ICE detainee and critically injured two others.

FBI officials searched Jahn’s residence and bedroom, officials said. Investigators found that Jahn had conducted multiple searches of ballistics and the video of Kirk being shot and killed during a campus event in Utah, which took place two weeks before Wednesday’s shooting, FBI Director Kash Patel wrote on social media.

Patel also wrote that Jahn had downloaded a document entitled “Dallas County Office of Homeland Security & Emergency Management”, which contains a list of Department of Homeland Security facilities. Since Sept. 19, Jahn also searched several mobile apps that tracked the presence of ICE officers.

The FBI also found evidence that demonstrated a high level of planning ahead of the attack.

A handwritten note found at the residence read, “Hopefully this will give ICE agents real terror, to think, ‘is there a sniper with (armor-piercing) rounds on that roof?” 

Jahn’s older brother, Noah Jahn, told Reuters on Wednesday that he was not aware that his brother harbored any negative feelings about ICE.

“I didn’t know he had any political intent at all,” said the older brother, who lives in McKinney, Texas, around 30 miles north of Dallas, as did his sibling.

This is a developing story. will update the story as more information becomes available.