FBI arrests protester who threatened to kill ICE officer's family at NJ detention center protest, Blanche says

The arrest came just hours after Blanche promised the protester, who was captured on video, would be found and arrested.

Blanche said the officer was just doing his job and "standing there."

He has not yet been identified.

Approximately 100 protesters mobbed the area surrounding the detention center, chanting "F--- ICE" and brandishing black umbrellas, gas masks and other gear to protect themselves from pepper spray and various anti-riot measures.

DHS has denied those claims.

Fox News' Charles Creitz and Robert McGreevy contributed to this report.