Multiple sensors can be deployed along a path so agents can tell the direction of travel and get an idea of how large a group is involved, he said. Then agents can either get ahead of the group or come in from behind and use night-vision goggle sand infrared cameras to spot them.
Border Patrol agents often are posted several hundred feet and even miles away from the border to look for people who sneaked into the country. Once smugglers get past several layers of enforcement, they typically hook up with a driver on a highway or ranch road and use back roads to make their way around Border Patrol checkpoints.
In the county where the shooting occurred, checkpoints could be seen on two highways that carry traffic to and from Interstate 10.
Drug-sniffing dogs and agents screen traffic passing through the checkpoints, resulting in searches of vehicles if there are indications of smuggling activity. But the checkpoints’ real enforcement purpose is indirect, Stoddard said.
‘‘The real purpose of the checkpoint is to get the dope or people on foot in a remote area where they can be picked up. It’s gravy when a load goes into the (checkpoint).’’