Police Officer Heather Tolth gestured toward a small collection of neat, modular homes while driving her SUV on a road cutting through sage-covered plains in the 27,000-square-mile Navajo Nation. "That's a good family," she said with a smile. "We don't know the good families." Beyond the highway, dirt roads can be treacherous, and people live in small collections of homes with their extended families. There are often only three Navajo officers on duty in Tolth's district, and it can take them two to three hours to respond to 911 calls.