EL PASO, Texas » A federal appeals court ruled Monday that a Mexican teenager killed by a Border Patrol agent was protected by the U.S. Constitution, even though the teen was on Mexican soil when he was shot.

The ruling from the 5th U.S. Circuit Court of Appeals means the family of 15-year-old Sergio Adrian Hernandez Guereca can move forward with a civil lawsuit against the agent.

"This recognizes human rights belong to everyone. Not just American citizens," or people standing on U.S. soil, said Bob Hilliard, one of the lawyers representing the family.

The original lawsuit was filed against the Border Patrol, the Department of Homeland Security, Customs and Border Protection, agent Jesus Mesa and the U.S. Department of Justice. But part of the ruling relieves the agent’s supervisors and the agencies from responsibility.

"The appellants (do not point to) any other evidence that would suggest that the supervisors were personally responsible for the alleged constitutional violation," the ruling says.

Hilliard said the family will likely appeal that part of the ruling.

Both the government and Mesa can also appeal the ruling. The Border Patrol said it would not comment on the matter as it opens the possibility of litigation. Mesa’s attorney did not immediately respond to requests for comment from The Associated Press.

Mesa shot Hernandez in 2010 near a border bridge between El Paso and Ciudad Juarez while trying to arrest immigrants who crossed illegally into the United States. Mesa said he was attacked by rock throwers. Border Patrol agents are allowed to shoot at rock throwers if they feel their lives or those in their custody are at risk.

U.S. District Judge David Briones found in 2011 that the family could not sue because the shooting’s effects were "felt in Mexico." But the appeals court said that "territorial approach" would allow agents to establish "zones of lawlessness."

It "would establish a perverse rule that would treat differently two individuals subject to the same conduct merely because one managed to cross into our territory," the appeals court ruling says. It also says that giving people standing on Mexican soil protection from "conscience shocking" actions by border agents, such as the shooting of Hernandez Guereca, is not a new policy. Immigrants who are inside the U.S., even those who are to be removed from the country, "are entitled to feel free of gross physical abuse by federal agents," it says.

Extending that right to people injured across the border by U.S. agents standing on U.S. soil, would inform the officials that they are not allowed to arbitrarily inflict harm in this "new, but similar, context," the court said.

"Today the Fifth Circuit helped ensure that CBP agents are held accountable for shocking and outrageous abuse, even when their victims aren’t inside the U.S. … The Fifth Circuit clearly signaled that Border Patrol cannot operate with impunity," American Civil Liberties Union senior staff attorney Adriana Pinon said in a statement. The ACLU was not directly involved but filed a friend of the court brief in the case.