The suspect was also linked to a location in Oklahoma. A family member said the 29-year-old wasn’t known to have strong political leanings.

Police responded to shots fired at the U.S. Immigration and Customs Enforcement office in Dallas about 7 a.m. local time.

Joshua Jahn, 29, opened fire from a rooftop on a bus carrying migrants into a Dallas ICE facility under federal escort before taking his own life.

Patel said the FBI has been "working 24/7 to seize devices, exploit data, and process writings" obtained from the suspect.

The shooting suspect was identified as 29-year-old Joshua Jahn, multiple law enforcement sources told ABC News.

Asked if Jahn was anti-ICE as evidence so far indicates, the relative shook his head and said, "it has nothing to do with that."

The gunman who fatally shot an ICE detainee and wounded two others at a Dallas facility early Wednesday has been identified as 29-year-old Joshua Jahn, law enforcement sources told multiple outlets, including NBC News.

Authorities are reportedly investigating a bizarre sign on a vehicle believed to be Dallas ICE shooter Joshua Jahn's.