Notes written by the person who opened fire on an immigration facility in Texas indicate he was targeting ICE agents and did not intend to harm detainees, officials 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.
The suspected gunman died of a self-inflicted gunshot wound, law enforcement officials said.
Speaking at a news conference on Thursday, acting US attorney for the Northern district of Texas, Nancy Larson, identified the shooter as 29-year-old Joshua Jahn, of Fairview, Texas.
Notes found at the shooter's home show he intended to maximise lethality against ICE personnel and to maximise property damage at the facility, she said.
He hoped to minimise any collateral damage or injury to the detainees and any other innocent people, she added.
It is clear from these notes that he was targeting ICE agents and ICE personnel. The victims have not yet been identified. However, Mexico's foreign ministry has said one injured detainee is a Mexican national.
Officials had previously stated that no law enforcement officers were injured or killed during the incident.
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 stated: 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.
She praised ICE and other federal agents for their swift actions under fire to evacuate detainees.
Tensions have escalated at ICE facilities in recent months amid Trump's efforts to significantly increase deportations as part of a wider crackdown on illegal immigration.
