From breitbart.com:
Exclusive details have emerged on the early morning attack against Border Patrol agents that left one agent dead and another hospitalized in serious condition on November, 19 2017. Breitbart Texas first broke the news of the death and injuries and now the National Border Patrol Council (NBPC) says that their agents on the ground have stated that the agents were tracking a group of illegal aliens who then beat the agents with rocks until one was killed and the other hospitalized.
