Leader of armed group stopping migrants at U.S.-Mexico border to face federal charges

The leader of an armed group that is stopping undocumented migrants crossing into the United States from Mexico is expected in court on Monday as federal prosecutors crack down on civilians attempting to enforce immigration policy.

The FBI on Saturday arrested Larry Hopkins, leader of the United Constitutional Patriots group, whose camouflage-wearing armed members claim to have helped U.S. officials detain some 5,600 migrants in the last two months.

The group claims to be working in support of President Donald Trump's crackdown on immigration. Last week it drew the criticism of New Mexico's Democratic Governor Michelle Lujan Grisham and the American Civil Liberties Union, which accused it of illegally detaining migrants.

Hopkins, a 69-year-old who also goes by the name Johnny Horton, was arrested in Sunland Park, New Mexico, on a federal complaint charging him with being a felon in possession of firearms and ammunition, the Federal Bureau of Investigation said in a statement.

He is expected to appear in federal court in Las Cruces, New Mexico, at 10:30 a.m. local time (1630 GMT).