A gunman fired several shots on a U.S. Immigration and Customs Enforcement field office in Dallas this morning, killing one detainee and critically wounding two others. Officials said the gunman died of a self-inflicted gunshot wound. No law enforcement agents were hurt.

The gunman — whom the authorities described as a sniper who had fired “indiscriminately” from a nearby rooftop — left behind ammunition that bore the phrase “ANTI-ICE” in blue writing, according to investigators. Officials suggested that it was a targeted attack aimed at immigration enforcement agents.

Three people familiar with the investigation identified the shooter as Joshua Jahn. Jahn was 29, one of the people said. At a speech in North Carolina, Vice President JD Vance said that there was “some evidence that we have that’s not yet public, but we know this person was politically motivated.”

Witnesses described the frantic moments of the shooting, hearing rapid gunfire and taking cover in their cars until officers escorted them inside. “It was one shot after another after another after another,” one said.

The shooting was the second at a federal immigration facility in Texas in recent months. A police officer was shot in July outside an ICE detention facility in Alvarado, Texas. More than a dozen people have been charged in that attack.