. >> reporter: captain stacy holland and his team from the texas department of public safety are trying to stop drug smugglers from crossing from mexico into the u.s. >> right there, right there. one guy's gotten out. >> reporter: they are also trying to stop the violence of a full-scale drug war from spilling north. >> are there parts of this border that you would be basically lawless or run by the cartels? >> absolutely. >> reporter: smack in the middle of this 21st century version of the wild west, two young americans, david hartley and tiffany young, just teenagers when they fell in love. >> we started dating in '98. the summer of '98, and dated for quite a while before we got engaged in 2001 and married in 2002. >> what took so long? >> we were 18. >> reporter: they wound up here, in the mexican border town of reynosa, jut south of mcallen. he was a district manager for an oil company. >> it was a blessing to us and our marriage. yeah. we were -- that's where we truly grew as a couple and had adventures. >> reporter: when the hartley's first arrive here this peaceful town was a per

. >> reporter: captain stacy holland and his team from the texas department of public safety are tryingo stop drug smugglers from crossing from mexico into the u.s. >> right there, right there. one guy's gotten out. >> reporter: they are also trying to stop the violence of a full-scale drug war from spilling north. >> are there parts of this border that you would be basically lawless or run by the cartels? >> absolutely. >> reporter: smack in the middle of this 21st century version of the wild west, two young americans, david hartley and tiffany young, just teenagers when they fell in love. >> we started dating in '98. the summer of '98, and dated for quite a while before we got engaged in 2001 and married in 2002. >> what took so long? >> we were 18. >> reporter: they wound up here, in the mexican border town of reynosa, jut south of mcallen. he was a district manager for an oil company. >> it was a blessing to us and our marriage. yeah. we were -- that's where we truly grew as a couple and had adventures. >> reporter: when the hartley's first arrive here this peaceful town was a perfe