Choppers, dogs and towers: Inside the Fed's fight against illegal immigrant intruders

SUNLAND PARK, N.M. — As Border Patrol agents work to combat the movement of illegal immigrants across the southern border in the El Paso Sector, they say a multi-layered enforcement system that has been expanded in recent years and combines the use of barriers with technology and other forms of enforcement has helped thwart cartel smuggling operations and nab illegal immigrants moving into the U.S.

Overshadowing the border in Sunland Park, New Mexico, is miles of border wall. Some of it...