sharyl: he was assigned to operation greenup, an oss mission to drop three spies behind enemy lines in austria. now, a handful of heroes are running down the clock hoping for well-deserved recognition. >> it means that at least somebody thinks that we did a good job. [captioning performed by the national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org] ? sharyl: welcome to "full measure." i'm sharyl attkisson. securing the southern border is a top priority for president-elect donald trump. promised wall will take remains to be seen. already, there's an army of federal agents guarding the line between the u.s. and mexico. their top priority -- keeping terrorists and their weapons out. today, we explore the risk of border agents getting corrupted and crossing the line to the dark side. customs and border protection is the largest federal law enforcement organization in the u.s. 60,000 employees secure more than 100,000 miles of borders and coastline. but to criminal drug cartels, all that securitlo like opportunity. jeff veltri: we have a