Federal immigration authorities plan to crack down on illegal immigrants who legally entered the United States but failed to leave when their documents expired, a move that comes in the aftermath of the terrorist attack by an Egyptian visa overstayer in Boulder, Colorado.

Todd Lyons, acting director for U.S. Immigration and Customs Enforcement, revealed in the hours after an Egyptian national used a flamethrower to torch Jewish residents in Boulder on Sunday afternoon that the Trump administration had moved to target visa overstayers.

“There’s a big push right now at ICE to identify all these individuals that have overstayed their visas. We have millions that have come in, you know, all across the last administration that have overstayed their visas and overstayed their welcome,” Lyons said during an interview on Fox News Monday. “One of the main missions of ICE is to go ahead and arrest anyone that we can take an enforcement action [against], that has violated immigration immigration law.”