Dallas shooter intended target to be ICE not detainees - officials

Notes written by the person suspected of opening fire on an immigration facility in Texas indicate he was targeting ICE agents and did not intend to harm detainees, acting US attorney for the Northern district of Texas Nancy Larson said.

One detainee was killed and two others critically injured after a suspected sniper opened fire at an Immigration and Customs Enforcement (ICE) centre in Dallas on Wednesday, officials said.

Speaking at news conference on Thursday, Ms Larson identified the shooter as 29-year-old Joshua Jahn, adding notes he had written had been found at his home.

She said he intended to "maxmise lethality against ICE personnel and to maxmise property damage at the facility".

"He hoped to minimise any collateral damage or injury to the detainees and any other innocent people," she added.

"It seems that he did not intend to kill the detainees or harm them. It is clear from these notes that he was targeting ICE agents and ICE personnel."

The victims have not yet been identified.

FBI director Kash Patel said in a post on social media earlier that evidence "to this point indicates a high degree of pre-attack planning".

Patel said one of the handwritten notes found said: "Hopefully this will give ICE agents real terror, to think, 'is there a sniper with AP rounds on that roof?"

At the news conference on Thursday, Larson said the shooter "very likely acted alone".

"That morning gunshots sprayed the length of the building, the windows, and law enforcement vans that were in the sallyport area," she said, adding detainees were hit.

The notes were found at the shooter's residence, and included a "gameplan of the attack", she said.

The suspected shooter described ICE employees as "people showing up to collect a dirty pay check" according to Ms Larson.

She said the shooter had hoped his actions would "terrorise ICE employees and interfere with their work".

"What he did is the very definition of terrorism," she added.

No evidence was found of membership of any specific group, and the shooter did not mention any specific government agency other than ICE, she said, but the man did express his hatred of the federal government.

She also praised ICE and other federal agents she said worked under fire to remove detainees from vans and get them to safety.

FBI special agent Joe Rothrock said it was a "targeted, ambush-style attack on law enforcement".

The shooter "specifically intended to kill ICE agents" and fired at transport vehicles carrying ICE personnel, federal and detainees, he said.

"Jahn also acknowledged the potential for other casualties. He knew with a high likelihood ICE detainees would be transported that morning in the exact location where he was facing from his perch on a nearby rooftop," he said.

Marcos Charles, ICE field office director of enforcement and removal operations, said "violent rhetoric" against ICE has to stop.

"In contrast to those who would demonise our men and women, yesterday our brave officers ran back into danger," he said, alongside other federal agents, "to save the detainees while shots were still being fired."