Dogs can use their keen sense of smell to help law enforcement as part of teams called K-9 units. A mysterious bag in an airport? A car full of hidden drugs? A missing body in the woods? Don't worry, K-9 Units are on the case! In this high-interest, lower-reading level series, readers get an exciting look into what FBI agents do, how medical examiners perform an autopsy, what K-9 units can really sniff out, and more. Glossary words are defined on the page where they appear, boosting reader comprehension.