Victor Clark-Alfaro, a lecturer at San Diego State and director of Tijuana’s Binational Center for Human Rights, began doing field work with human smugglers along the U.S-Mexico border in the late 1980s. In a Q-and-A, he discusses the business of smuggling people across the border, including the role of referrals and pricing and how it’s all changed in recent years.

The chief of San Diego’s Border Patrol section said he can’t disclose what agents look for before stopping someone, but that race and ethnicity don’t come into play. A review of enforcement actions recorded between 2011 and 2014, though, shows agents stopped people for sometimes ambiguous reasons like sitting up straight or driving slowly.

Despite a Sheriff’s Department policy that prohibits deputies from stopping, detaining or questioning people for reasons related to immigration, deputies contacted U.S. Border Patrol during a traffic stop and held the couple until agents arrived on scene to detain them.

Border Patrol agents we spoke to aren’t sure how a border wall will change the dynamics between law enforcement and people trying to evade them. But drug tunnels, patches to the border fence and rings of concertina wire serve as reminders that for every measure taken to fortify the border, there have always been countermeasure to get around them.

If you take one high-profile count of the region’s homeless at face value, you’d assume homelessness in the South Bay is dropping. But a closer look reveals many homeless families there are hidden out of sight, a reality that has real implications for some of the most vulnerable populations in the South Bay.