TAOS, N.M., April 22 (Reuters) - 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).
The group he leads, the UCP, describes itself as a "patriot group" helping U.S. Customs and Border Patrol cope with record numbers of Central American families crossing the border to seek asylum. It has had around half a dozen members camped out on a rotating basis near Sunland Park since late February.
Videos posted online by the UCP show members telling migrants to stop, sit down and wait for agents to arrive. Critics accuse the UCP of impersonating law enforcement.
UCP spokesman Jim Benvie blamed Hopkins' arrest on political pressure from Lujan Grisham.
U.S. Customs and Border Protection said in a weekend statement that it did not support citizens taking law enforcement into their own hands, and instead encouraged them to report suspicious activity to officials.
"The rule of law should be in the hands of trained law enforcement officials, not armed vigilantes," New Mexico Attorney General Hector Balderas said in a statement.
Hopkins was previously arrested in Oregon in 2006 on suspicion of impersonating a police officer and being a felon in possession of a firearm, according to the Southern Poverty Law Center.
Benvie described the UCP as mostly made up of military veterans who he said carry firearms for self defense. He denied that members of the group had pointed weapons at migrants. (Reporting by Andrew Hay in Taos, New Mexico, writing by Scott Malone; Editing by David Gregorio)