The acting U.S. attorney for the Northern District of Texas called Wednesday’s shooting at a Dallas Immigration and Customs Enforcement (ICE) facility the “very definition of terrorism” on Thursday. 

In notes that investigators found at the shooter’s home, the gunman “hoped his actions would terrorize ICE employees and interfere with their work,” acting U.S. attorney Nancy Larson said at a press conference.

The shooter, whom officials identified as 29-year-old Joshua Jahns, opened fire at the facility and a van transporting detainees from a nearby rooftop. Jahns, from Collin County, Texas, died of a self-inflicted gunshot wound before local law enforcement officers could apprehend him.

One detainee was killed, while two are in critical condition. Officials said Thursday that ICE and Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) removed detainees from the van while under fire. 

Larson noted that based on his writings, Jahns did not intend to harm any detainees, but instead aimed, “to maximize lethality against ICE personnel, and to maximize property damage at the facility.”

Joseph Rothrock, the FBI special agent in charge at the Dallas field office, said at the press conference that the shooter’s notes indicate he did not plan on surviving the attack. 

Rothrock added that while an investigation is ongoing, it is clear that a “significant, high degree of planning,” went into the attack. Earlier Thursday, FBI Director Kash Patel unveiled evidence that the gunman searched apps that track the presence of ICE agents from Aug. 19 to Aug. 24 and downloaded a document on Wednesday and Thursday that lists ICE facilities in Dallas. 

Patel also said Wednesday that one of the unspent shell casings recovered at the scene had “ANTI-ICE” inscribed on it. Larson added that Jahns expressed hatred of the federal government in his writings, but did not mention any other agencies besides ICE.

She also said that investigators have not found evidence Jahns was part of an organized group or entity. President Trump, in a Truth Social post on Wednesday, blamed “left wing domestic terrorism” for the shooting.

“He doesn’t want to just impact the ICE and the law enforcement agents that were carrying out that mission yesterday,” Rothrock said. “He wants to impact ICE agents and law enforcement across the country.”

Larson added that Wednesday’s shooting was the third attack or threat on an ICE facility in her district since she took office in May. On July 4, a local law enforcement officer was shot during an attack on an ICE detention center in Alvarado, Texas. Over a dozen people have been arrested in connection with the incident, while the officer was later released from the hospital. 

Last month, a man was arrested after faking a bomb threat at the same ICE facility where Wednesday’s shooting occurred.

Marcos Charles, the acting head of ICE’s Enforcement and Removal Operations, said at Thursday’s press conference that “violent rhetoric” has led to a greater than 1,000-percent increase in assaults against ICE officers. Since Trump took office in January, there have been nationwide protests against ICE raids.

“We call on those who foment violence and vilify our law enforcement officers to cease the dangerous rhetoric,” Charles said.

Officials said the investigation into the shooting is ongoing.