Authorities are searching for Song in connection with an attack outside a U.S. Immigrations and Customs Enforcement detention facility in Texas on July 4.

The suspect wanted in a recent ambush on an ICE facility is a long-time Antifa member, connected to several left-wing militant groups.

The July 4 attack is just one in a series of recent attacks against federal immigration officers. On Monday, July 7, U.S. Border Patrol agents in the Rio Grande Valley fatally shot a Michigan man who launched an attack at their McAllen facility before dawn.