Trackers.

This is coolbert:

Along the "porous" border between Mexico and the U.S., tracker units and mounted units of horsemen are now being put into play.

These are quasi-military units.

Well, they might as well be military units.

Look military, that is for sure.

The tracking units are comprised of American Indians who are really outdoors types.

Able to track people and find them like something you would see out of a western movie. Armed with M-16's because of the nature of the work and the prey they are after, drug smugglers for the most part. Now,

Mounted units are also desirable for this type of work.

Patrols can go out into a wilderness, roadless area, and stay out for extended periods of time without the need for resupply. Operate relatively silently. And I would think that the rider and horse become one with the environment. Not a bad idea for law enforcement. I bet the riders become much more attune to their surroundings and changes in same than they would otherwise. Become much more effective. All their senses become alert to their surroundings. On patrol, they will be looking for fresh footprints, tire tracks, campsites, etc. In the olden times, this would have been called, "looking for sign".

coolbert.