The fatal shooting of Alex Pretti by Border Patrol agents has further inflamed tensions in Minneapolis, a city at the center of America's immigration debate in recent months. Here's a look at how it started.

The border czar was dispatched early last week to Minnesota to attempt to find a solution to the tensions that have roiled the state in the wake of two fatal shootings involving federal agents. Agents from Immigration and Customs Enforcement and Customs and Border Protection have been carrying out Operation Metro Surge in the state.