Picnickers in a riverside park in Nuevo Laredo, Mexico, react in horror as a man in a yellow baseball cap named Guillermo Arevalo lies on the bank of the Rio Grande, bleeding to death.

It’s a warm Monday evening in September 2012. He has just been shot by an agent on a U.S. Border Patrol airboat on the river. The Border Patrol says the agent shot at rock throwers and that the incident is under investigation.

U.S. Border Patrol Scrutinized For Increasing Fatalities

Witnesses say Arevalo was not throwing rocks. A woman, unseen in a jerky cellphone video, begins to scream before she’s drowned out by the boat’s deafening engine.

“That’s against the law!” she shrieks, repeatedly.

This is exactly the controversy confronting the Border Patrol these days as a chorus of critics asks: Are federal officers who guard the territorial borders of the United States above the law?

Many agents risk their lives securing the border, but they also face uncomfortable questions about their use of force.

via U.S. Border Patrol’s Response To Violence In Question : NPR.