Shortly before midnight on Wednesday, a stocky 16-year-old Mexican boy died face down on a pitted concrete sidewalk in Nogales, Sonora, Mexico. José Antonio Elena Rodriguez had been shot seven times. His alleged killer, a U.S. Border Patrol agent, had gunned him down from the Arizona side of the border.

The Border Patrol, in a statement to The Daily Beast, claims the FBI is investigating the shooting, which began when Border Patrol agents came upon smugglers dropping loads of narcotics in Nogales, Ariz. As the smugglers hightailed it back into Mexico, the agents were “assaulted” with rocks from the Mexican side, the statement says. The agents ordered the rock throwers to “cease.” When the rocks kept coming in from Mexico, an agent “discharged his service weapon.” The Border Patrol did not say an agent killed the boy, but said instead “one of the subjects appeared to have been hit.”

The unlikely scenario of Border Patrol agents in the United States gunning down Mexican rock throwers in Mexico has played out several times in the last two years, outraging the Mexican government, raising questions about the Border Patrol’s use of force, and causing diplomatic huddles between the two countries.

“This is happening with a disturbing frequency,” a high-placed Mexican official who is very familiar with the Rodriguez shooting investigation tells The Daily Beast. “It’s about use of force. How much of a threat is a rock compared to a firearm?”

Not counting the Rodriguez case, in the last two years, Border Patrol agents in the United States have reportedly shot and killed at least three Mexicans in Mexico, and injured at least one other, according to press reports. In each case, rocks were allegedly thrown from Mexico into the United States either as a way to divert agents from arresting Mexicans or as a mean-spirited taunt.

At least one other killing may have occurred in Nogales, Sonora, Mexico. On Jan. 5, 2011, a Border Patrol agent shot and killed 17-year-old Ramses Barron Torres when he and others on the Mexican side of the fence allegedly began throwing rocks at Border Patrol agents making a drug bust in the United States, according to Nogales International newspaper.

A year before, a Mexican teen was shot and killed by a Border Patrol agent on the Mexican side of the Rio Grande in Juarez, Chihuahua, Mexico. The agent claimed the boys were running into the United States, then running back into Mexico. When he grabbed one of the boys, the agent said, the others began throwing rocks at him. He fired. The family filed a wrongful-death lawsuit against the agent in the United States, but it was dismissed, according to the El Paso Times, because the shooting occurred in Mexico.

Another fatal shooting occurred in September. A Mexican man on the Mexico side of the Rio Grande near Nuevo Laredo was shot by a Border Patrol agent aboard a boat in U.S. waters, according to the San Antonio Express-News. The family said the man was picnicking; the Border Patrol said the victim was pelting the agent with rocks.

The Mexican official familiar with all the investigations tells The Daily Beast that in addition to the shootings in Mexico, in the last six years, more than two dozen Mexicans have been “shot, Tazered, or otherwise abused” by Border Patrol agents and other law enforcement officials on the American side of the border. Very often, rock throwing is part of the scenario. Since the shootings are found to be justifiable by U.S. officials, the message to Border Patrol agents is, “it’s fair game for a Border Patrol agent to shoot a Mexican,” he says.

“What would happen,” the official asks, “if the tables were turned? What would happen if an American teenager threw rocks at a Mexican agent and the Mexican agent shot the American? This is the question we always ask Americans.”

Mexican leaders met Friday in Mexico City to discuss the Rodriguez killing, according to The Arizona Republic, and the shooting has been roundly condemned by all levels of Mexican government. In Washington on Thursday, the Mexican Embassy issued a blistering statement saying preliminary information about the Rodriguez shooting raises “serious doubts about the use of lethal force by U.S. Border Patrol agents, something that both the Mexican Government and Mexican society strongly deplore and condemn.”

The shootings have sparked “conversations” between the United States and Mexico, says Christopher Wilson, an expert on Border Patrol issues and associate in the Mexico Institute Woodrow Wilson Center in Washington. No one wants to deprive the Border Patrol of the use of weapons to deter and defend, says Wilson. But the shootings “have happened several times” and bear similarities—young victims, rock throwing, and a debate over whether the victims were really rock throwers, narco-traffickers, or innocent bystanders.

“There’s a lot of space for conversations on creative ways” for the United States to manage Border Patrol “protocols,” Wilson says, so such incidents don’t occur in the future.

At least one method—shooting things other than bullets—seems to work. Last year, a Nogales-based Border Patrol agent “used a pepper ball launcher to repel a rock-throwing smuggling suspect and seize $12,500 worth of marijuana,” the Nogales International reported.

No one was injured.