Other than their mode of entry to the United States, is there a material difference between illegal immigrants who cross the border illegally and those who legally enter the U.S. and then illegally overstay their visas?
Numerous activists and media outlets have claimed that robust border security is pointless because many illegal immigrants legally enter the U.S. by using visas and then don't leave when their visas expire. Such claims are misleading because all visa entrants are screened by the U.S. government to keep out foreigners who pose risks to the health and safety of Americans, while illegal border crossers are not. This lack of screening allows criminals to enter the U.S., and hundreds of thousands of them have committed violent crimes in the United States. "Removable criminal aliens" are non-citizens who have been convicted of crimes in the U.S. that warrant immediate deportation hearings. Based on data from 2007 to 2009, the Obama administration Department of Homeland Security estimated in 2010 that about "1.94 million removable criminal aliens are in the United States today."