contribute to the greater numbers. we re seeing so many people. reporter: arizona department of public safety has deployed to these parts of the border to monitor for criminal activity. out here, we re watching the desert, looking for movement, looking for any signs that that we have. of a group coming through. reporter: on this 75-mile stretch of the border, major cecil and his troopers try to fill in the dpgaps. what we re seeing say surge of illegal drugs. because border patrol is tied up they know that manpower out here is limited. reporter: this week, the biden administration is expected to send 100 agents here. for carlos and this group of migrants, getting on the bus is their best bet. for a better future. many of the migrants that are arriving here are middle class families from south america. and they re carrying suitcases