A divided Supreme Court deferred to Congress on Tuesday when it comes to allowing lawsuits arising from cross-border law enforcement incidents, in a case where a U.S. Border Patrol agent in 2010 shot and killed a 15-year-old Mexican boy who was on the Mexico side of a concrete culvert that sits on the international border.

The boy’s parents sought damages in a lawsuit filed in a federal court in Texas that alleged the agent used excessive force. A Supreme Court precedent from 1971 allows such claims against federal agents who are accused of infringing on constitutional rights, even though no federal law authorizes those lawsuits.

But in a 5-4 opinion issued Tuesday, the Supreme Court declined to extend that precedent for those injured on foreign soil, since the issue involves foreign relations and national security implications of policing the country’s borders.

[Appeals court rules in favor of Trump family planning rule]

Congress has refrained from authorizing damages for injuries government officers inflict abroad, and left the resolution of extraterritorial claims brought by foreign nationals to executive officials and the diplomatic process, Justice Samuel A. Alito Jr. wrote for the majority.

“Congress’s decision not to provide a judicial remedy does not compel us to step into its shoes,” Alito wrote.

The majority opinion, joined by the four other justices who make up the court’s conservative wing, pointed to the “daunting task” of attempting to control the movement of people and goods across the border.

Alito wrote that about 850,000 people were apprehended while attempting to enter the United States from Mexico in the last fiscal year, while large quantities of drugs were smuggled and powerful criminal organizations operated on both sides of the border.

“Since regulating the conduct of agents at the border unquestionably has national security implications, the risk of undermining border security provides reason to hesitate before” the courts would allow such lawsuits when Congress has not, Alito wrote.

[Court tosses lawmaker lawsuit against Trump over emoluments]

He pointed out that both the United States and Mexico have concerns about how the shooting was resolved, and those have been addressed through diplomatic channels. “It is not our task to arbitrate between them,” Alito wrote.

The 15-year-old, Sergio Adrián Hernández Güereca, was with a group of friends in a culvert that separates El Paso, Texas, from Ciudad Juárez, Mexico, according to the opinion. The border runs through the center of the culvert, which is largely dry but was designed to hold the waters of the Rio Grande River.

Border Patrol Agent Jesus Mesa Jr. detained one of the boy’s friends who had run onto the U.S. side of the culvert and fired two shots at Hernandez as the boy ran back across the culvert onto Mexican soil.

Justice Ruth Bader Ginsburg, in a dissent joined by the three other justices who make up the court’s liberal wing, wrote that the boy’s exact location in the culvert when he was shot “should not matter one whit” when the United States has jurisdiction to govern a Border Patrol agent’s conduct in this country.

The agent’s “allegedly unwarranted deployment of deadly force occurred on United States soil,” Ginsburg wrote. “It scarcely makes sense for a remedy trained on deterring rogue officer conduct to turn upon a happenstance subsequent to the conduct — a bullet landing in one half of a culvert, not the other.”

Ginsburg also contested the majority opinion’s conclusion that border security would be undermined by allowing a lawsuit under the 1971 precedent, Bivens v. Six Unknown Fed. Narcotics Agents, for an unjustified shooting.

“Instructions regulating Border Patrol agents tell them to guard against deploying unjustified deadly force,” Ginsburg wrote. “Given that instruction, I do not grasp how allowing a Bivens action here would intrude upon the political branches’ national-security prerogatives.”

The boy’s family says the friends were “simply running across the culvert, touching the fence on the U.S. side, and then running back across the border,” Alito wrote in the opinion. “According to Agent Mesa, Hernández and his friends were involved in an illegal border crossing attempt, and they pelted him with rocks.”

The Justice Department concluded that Mesa had not violated Customs and Border Protection policy or training and declined to bring charges or take other action against him, Alito wrote. Mexico requested that Mesa be extradited to face criminal charges in a Mexican court, and the United States denied that request.

Ginsburg, in the dissent, warned that “it is all too apparent that to redress injuries like the one suffered here, it is Bivens or nothing.”

The decision will affect other cases, said Lee Gelernt, an American Civil Liberties Union lawyer who represents another 15-year-old shot in Mexico by a border agent who was on the U.S. side of the border fence.

“The gravity of this ruling could not be clearer given the Trump administration’s militarized rhetoric and policies targeting people at the border,” Gelernt said in a news release.

“Border agents should not have immunity to fatally shoot Mexican teenagers on the other side of the border fence. The Constitution does not stop at the border.”