By Andrew Chung
WASHINGTON (Reuters) - Supreme Court justices appeared divided on whether to let foreigners bring civil rights lawsuits in U.S. courts as they considered a bid by a slain Mexican teenager's family to revive a lawsuit against the Border Patrol agent who shot him, with Justice Brett Kavanaugh emerging as a potential pivotal vote.
The court heard arguments in the family's appeal of a lower court's ruling dismissing their case against the agent, Jesus Mesa, who had fired across a concrete spillway into Mexico from the Texas side of the border during the 2010 incident, striking 15-year-old Sergio Adrian Hernandez Guereca in the face.
The case comes to the court at a time of high tensions involving the southern border, where Republican President Donald is pursuing construction of a wall separating the United States and Mexico. His administration, backing the U.S. Border Patrol agent, has said giving foreigners the chance to sue could pose problems for national security and international relations.
During the arguments, conservative justices appeared to lean toward the administration's concerns while liberal justices voiced worry about leaving individuals with no way to hold federal officers accountable for unlawful conduct. The court has a 5-4 conservative majority.
Kavanaugh, appointed to the court by Trump last year, asked questions expressing sympathy for both sides, noting that there could be foreign policy implications even when a Mexican national is shot inside the United States.
The dispute hinges on whether the family, despite Hernandez having died on Mexican soil, can seek monetary damages against what they call a "rogue" agent for violating for the U.S. Constitution's Fourth Amendment, which bars unjustified deadly force as well as Hernandez's right to due process under the Constitution's Fifth Amendment.
For the family's lawsuit to move forward, the Supreme Court would have to widen the scope of its 1971 decision allowing certain suits against federal officials. That case, however, involved a domestic search.
The Supreme Court generally has been reluctant to extend the scope of civil rights protections. For example, it ruled in 2017 that former U.S. officials who served under President George W. Bush could not be sued over the treatment of non-U.S. citizen detainees rounded up in New York after the Sept. 11, 2001 attacks.
The high court previously considered Hernandez's case in 2017 but did not decide the central legal question, instead directing the New Orleans-based 5th U.S. Circuit Court of Appeals to reconsider its ruling that had barred the lawsuit. The 5th Circuit last year again ruled against the family, prompting a second trip to the Supreme Court.
On Tuesday, conservative Chief Justice John Roberts raised the international affairs issue, saying the government investigated the incident and cleared the officer of wrongdoing, but if the case proceeds a court could come to the opposite conclusion.
"I thought the country was supposed to speak with one voice," Roberts said.
Liberal Justice Elena Kagan pushed back against the idea that such an outcome could undermine the government's credibility with other nations.
"We live in a country where courts play an important role in determining whether conduct is lawful. And that is not an embarrassment to the United States or the executive branch," Kagan said.
The incident took place in June 2010 on the border between El Paso and Ciudad Juarez in Mexico. The Border Patrol said at the time Hernandez was pelting U.S. agents with rocks from the Mexican side of the Rio Grande when he was shot.
The lawyers for Hernandez's family dispute that account, saying he was playing a game with a group of teenagers in which they would run across a culvert from the Mexican side and touch the U.S. border fence before running back.
Mesa did not face criminal charges, though Mexico condemned the shooting.
(Reporting by Andrew Chung and Lawrence Hurley; Editing by Will Dunham)