Since The Daily Beast’s original “Lost Girls” investigation last summer, additional evidence and archives have been unearthed in the case. More than two dozen other victims were also reported in the same region of Panama, including a young woman from the United States found murdered earlier this year. Now a return trip to the scene of events—as well as renewed sleuthing by best-selling author Dr. Kathy Reichs and other forensic specialists—provide a fresh take on this cold case.

BOQUETE, Panama—We just hit the Great Divide, at about 4,000 feet, and anywhere we go from here it’s downhill all the way.

This bosky crest marks the spot where the country’s watersheds break for the Pacific Ocean in one direction, or the Caribbean in the other. From here the trail we’re following drops into a series of steep step-downs, a rugged mix of stony riverbeds and cattle traces that are off limits to tourists without a licensed guide. The far-flung, rainforest track is used chiefly by local ranchers and the region’s population of shy indigenous people known as the Ngobe.