More information is leaking out about the murder of the teenager at the border. From Yahoo News:

But two witnesses to the incident told the Wall Street Journal’s Nicholas Casey that Hernandez was standing on the Mexican side of the border with his hands up and had not thrown rocks at the agent.
U.S. national Bobbie McDow said she was in the middle of the Santa Fe Bridge — which spans the border and has security checkpoints at either side; and saw a group of teens who had no weapons or backpacks. They were playing a kind of “cat-and-mouse game,” trying to make it to the U.S. side and back to Mexico without being caught, she told the Journal.
McDow said two Border Patrol agents saw the group and chased them — and that one agent, riding a bicycle, caught and pinned down a suspect. She said the same agent then fired shots into Mexico, where the other boys had run. McDow said that one teen had thrown rocks at the agent but that Hernandez hadn’t.
McDow’s husband, Raul Flores, told the Journal he’d seen Hernandez emerge from behind a pillar on the Mexican side of the border with his hands up before the agent shot him in the shoulder and then in the head.

From the AP:

Hernandez was found 20 feet (six meters) into Mexico, and an autopsy revealed that the fatal shot was fired at a relatively close range, according to Arturo Sandoval, a spokesman for the Chihuahua state attorney general’s office. Mexican authorities said a .40 caliber shell casing was found near the body, suggesting that the Border Patrol agent might have crossed into Mexico to shoot the boy.
That would violate the rules for Border Patrol agents, who are supposed to stay on the U.S. side — and could open the agent to a Mexican homicide prosecution.

And from Democracy Now:

US authorities have said fifteen-year-old Sergio Adrian Hernandez Güereca was part of a group of boys throwing rocks at Border Patrol agents who were trying to detain two people at the border crossing. But a cell-phone video obtained by the Spanish language network Univision shows otherwise. The grainy footage shows the Border Patrol agent detaining one man at gunpoint. While he has the man on the ground, he points his gun toward a second person on the Mexican side of the border. The video shows that person running away as the agent fires several shots. The video then shows a body next to a column under the bridge. We speak to Fernando Garcia, the director of the Border Network for Human Rights.

I have to wonder, given the vehemence in which so many have argued that we must follow every single solitary law down the last drop–that we must punish those who break even those obtuse of laws–are we, as US citizens, going to hand over the border agent to be tried and convicted if it turns out he broke the law?