A federal grand jury has indicted on a weapons charge the leader of an armed group that has been detaining asylum-seeking families from Central America near the Mexican border.

The U.S. Attorney's Office in Albuquerque on Friday announced the indictment against Larry Mitchell Hopkins on a charge of being a felon in possession of firearms and ammunition. The indictment cites previous criminal convictions against the 69-year-old resident of Flora Vista, New Mexico, for impersonation of a police officer and firearms violations.

Hopkins was arrested April 20 in Sunland Park, New Mexico, near the U.S. border with Mexico where his group has been stopping migrants, ordering them to wait and alerting Border Patrol.

Hopkins is scheduled for arraignment Monday. Defense attorney Kelly O'Connell is representing Hopkins and says his client intends to dispute the charge.