The Supreme Court has ruled that the parents of Sergio Adrian Hernandez Guereca, the Mexican teenager who was slain over the border in Texas, cannot use American courts to sue on-duty U.S. Border Patrol Agent Jesus Mesa, Jr.

In 2010, Mesa shot Guereca at least twice in the face on the border between El Paso, Texas and Ciudad Juarez, Mexico. While Mexico condemned the shooting, Mesa did not face any criminal charges because at the time of the incident, people not in the United States were not allowed to file civil rights lawsuits in federal court.

Guereca’s family sued the federal government shortly after the shooting incident but the suit was dismissed early in the litigation.  At the time, tensions were high on the subject of the southern border and U.S. president Donald Trump was pushing for the construction of a wall that would separate the U.S. and Mexico.

While Mesa’s shooting of Guereca was undisputable, what remained in question and at the core of the legal dispute for years was whether the victim’s parents actually had a legal standing to sue Mesa for what he had done, considering that it took place outside the U.S. territory. Guereca’s parents argued that the federal agent’s use of excessive force violated their son’s Fourth and Fifth Amendment rights, which could have protected him from unreasonable search and seizure and assured due process protections.

Justice Samuel Alito described Tuesday’s 5-4 ruling against the parents of Guereca as “tragic,” sustained by strong border security and international relations issues. “Since regulating the conduct of agents at the border unquestionably has national security implications, the risk of undermining border security provides reasons to hesitate about allowing the parents to sue in American courts,” he explained.

During the litigation, Mesa maintained that he was only trying to stop smugglers who were attempting an illegal border crossing when he fired his gun at Guereca. The teenager was reportedly among the rock throwers at the border at the time, but video footage of the incident disproved his statement.

According to Guereca’s family, he was only playing a game with his friends that evening, running through a culvert and over the border, touching it, and running back. While he and his friends were busy playing, Mesa rode up on a bicycle and fired across the border, killing Guereca.

Family of Mexico teen shot by U.S. Border Patrol to sue Relatives and friends look at the body of 16-year-old Jose Antonio Elena Rodriguez in a coffin during his funeral in Nogales October 14, 2012. Reuters/Alonso Castillo