The Department of Homeland Security was established 20 years ago this week amid a wave of heightened focus on national security after 9/11.

Along the U.S.-Mexico border, the agency's creation intensified a crackdown along the U.S.-Mexico border known as Prevention Through Deterrence. 

The effort began in the 1990s as a set of border policies to deter people from crossing without permission. Urban areas were staffed with more Border Patrol agents and lined with walls. The same approach lives on today in the form of policies like the pandemic-era protocol Title 42 and asylum restrictions like the so-called transit ban currently being proposed by the Biden administration. 

Dora Rodriguez, a humanitarian worker and the founder of Tucson-based aid group Salvavision, says those steps didn't stop people from making the journey, and they don't now.

"Nothing will stop people from coming, if they’re fleeing fear, if they’re fleeing violence, or hunger," she said. "All I see is that this is really getting worse, the policies are changing, and the piece of humanity is missing."

Rodriguez fled her home in El Salvador amid the country's civil war in the '80s and almost died crossing the Arizona desert herself.  

"I remember when DHS came alive, it was with the idea that they were going to interrupt more terrorists and ... more drugs from coming into our country," she said. "But I'll tell you one thing, our asylum seekers, our migrants...who are leaving their countries because of violence or they're seeking a better life for their families...they're not terrorists, and they're not bringing drugs in their backpacks through the deserts."

Rodriguez says instead of stemming migration, these deterrence policies have only made the journey more deadly. At least 4,000 people have died crossing the border in Arizona alone since the 1990s, according to a count by the group Humane Borders. though experts warn the real number is likely much higher.