Next airing Wed Dec 9, 3 p.m. ET

The Front Lines

Officer Hector Navarro stops a silver pickup truck at the Nogales port of entry. The driver is acting suspiciously and traveling alone, which is a red flag. A police canine is called in to sniff for narcotics, and a cleverly hidden trove of heroin is uncovered - breaking an all-time record for drug busts at this port of entry.