Border security or border enforcement often brings to mind images of green and white-painted Border Patrol SUVs roaming across that contentious line between the United States and Mexico. But across South Texas, which I am defining as everything below San Antonio, border security is a vast apparatus involving multiple agencies across a wide swath of the state and affecting Texans of all backgrounds.

In a recent piece for Al Jazeera America I traveled across South Texas to render a portrait of life under border security. ”

On South Texas highways, where anti-littering signs warn: “Don’t Mess With Texas,” it is common to cross paths with a sheriff’s deputy, local police, Border Patrol agents, a county drug-task-force agent and one of the black state-trooper cruisers all within a few minutes.

Over the years, I had observed the growing presence of law enforcement across South Texas. Conversations with friends and family often turned to the frequent roadside stops and questioning by officers and agents. The story, however, crystalized after this incident:

The red pickup truck tears down the country road, mesquite trees and untamed brush all around. It bears a heavy load in the back, which officials later said provoked Texas game wardens to suspect drugs and give chase. Within minutes, a helicopter carrying state troopers — including a sharpshooter — joins the pursuit near a small town in the Rio Grande Valley on the border with Mexico.

“It’s got a tarp with what looks like [drug] bundles,” a voice says over the two-way radio. More details are supplied: southbound at 80 mph. The truck makes several turns before heading east on an unpaved road, according to an audio recording of the pursuit obtained by KRGV-TV, a local station. The truck charges east on Mile Seven. “We have a clear spot.” The radio goes silent for 14 seconds. Sharpshooter Miguel Avila takes aim at the pickup truck. “Shots fired! Shots fired!”

No “bundles” were found. The pickup truck was carrying a group of Guatemalan migrants who had slipped across the border in search of jobs further north. Two were killed.