In southern Arizona, a jury is deciding the fate of a U.S. Border Patrol agent accused of killing a teenaged boy by firing into Mexico from the United States.

Agents are frequently assaulted by people throwing rocks at them from Mexico. And agents have responded to those attacks. This case ended very differently with an agent now being charged by the government he works for. What's different?

To get the answer to this and other questions about the case, The Show turned to Michel Marizco, Fronteras Desk senior editor.