ICE shooter wrote about wanting to target agents he thought were involved in 'trafficking,' federal officials say

Joshua Jahn, who authorities say opened fire on a Dallas ICE facility, killing at least one detainee, might have been planning the attack for weeks.

When a Texas gunman fired on an Immigration and Customs Enforcement facility in Dallas, he was targeting federal employees he believed were collecting a "dirty paycheck" and involved in "human trafficking," officials said Thursday.

Federal officials said the gunman had been plotting his attack and knew how to locate the agents using ICE tracking apps.

Joshua Jahn, 29, made his intention for Wednesday’s attack clear in writings and through a trail left on his devices, federal officials said.

“Jahn specifically intended to kill ICE agents. ... He searched for information about the office building and how to track ICE agents’ locations,” said Joseph Rothrock, FBI special agent in charge.

“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.