NOGALES, Mexico - Jose Antonio Elena got the kind of punishment that those who toss rocks at Border Patrol agents receive with startling frequency: He was shot with a .40-caliber round from an agent's service weapon.
The bullet hit Elena in the back of the head. He slumped mortally wounded to a sidewalk on the Mexican side, a few paces from the border fence.
At least two agents, perched on the U.S. side about 20 feet above the street and shielded by the fence's closely spaced iron bars, continued to fire, witnesses said. In all, 10 bullets struck Elena, spattering a wall behind him with blood.
Yet Jose Antonio Elena may not have tossed any rocks at all. He may have been just walking on a sidewalk on Mexican soil, an innocent passer-by.
The Border Patrol has a video of the events that night, Oct. 10, 2012. The video likely shows whether U.S. agents killed an innocent Mexican or shot a member of a marijuana smuggling ring.
The agents remain on the job, neither publicly identified nor receiving any disciplinary action.
Elena's killing is one in a string of what critics say are unnecessary killings by Border Patrol agents along the U.S. border with Mexico. At least 21 people have died in confrontations with Border Patrol agents, often out of sight of witnesses or fellow agents, in the past four years.
Those cases include 10 people who've been killed for throwing rocks, according to the Border Patrol's own statistics, and there have been 43 cases since 2010 when agents have opened fire on rock throwers. But there are no known cases where an agent has been disciplined for improperly using force.
Border Patrol chief Michael Fisher defended his agents earlier this month, saying they had shown remarkable restraint and pointing out that they'd been pelted with rocks 1,713 times in the same period. Still, he issued a directive telling his agents to take cover, rather than open fire, when items are thrown their way.
He added, however, that rocks can be deadly projectiles, and agents may shoot when their lives are in danger.
The Border Patrol did not respond to requests for information about Elena's death. At the time of the shooting, it issued a statement saying that a lone agent had "discharged his service firearm" after suspected smugglers ignored "verbal commands from agents" to stop throwing rocks, according to an Oct. 13, 2012, story posted on the website of the local newspaper, the Nogales International.
The Border Patrol acknowledged then that surveillance cameras had captured the event and that the video had been turned over to the FBI.
A spokesman for the U.S. Attorney's Office in Arizona, Cosme Lopez, said he could "neither confirm nor deny" any information about the Elena killing, including whether an investigation was still open.
Critics are skeptical, however, about the Border Patrol's version. They note that in Elena's case, witnesses say that at least two agents fired, that both were well above whoever might have been throwing rocks, and that they literally stretched their arms across the border to shoot.
The agents fired between 25 and 30 rounds from their overlook, witnesses said - some apparently wildly, despite the scene being a busy downtown area. Pock marks can still be seen high on the wall of a nearby residence.
One witness on the Mexican side of the border calls Elena's death murder. Those tossing rocks ran down a side street, escaping before the shooting started, he said. Elena was walking on the sidewalk when the rock throwers darted past him.
"To me, it was cold-blooded murder," said Isidro Alvarado Ortiz, a 37-year-old security guard who said he was walking about 30 paces behind Elena when the agents opened fire.
Alvarado has given testimony to the FBI but like several Mexicans involved in the case, he has grown frustrated at the lack of U.S. action on the investigation.
"Imagine if it had occurred the other way around - if a Mexican had killed one of them. They would've come the next day to get the person," Alvarado said.