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 or 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 targeted ICE agents and ICE personnel.”
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.