In this Feb. 14, 2017 photo, The Supreme Court is seen at day's end in Washington.  The Supreme Court on Tuesday is hearing an appeal to a case involving a 2010 shooting of a Mexican boy by a U.S. Border Patrol Agent.  (AP Photo/J. Scott Applewhite)
In this Feb. 14, 2017 photo, The Supreme Court is seen at day's end in Washington. The Supreme Court on Tuesday is hearing an appeal to a case involving a 2010 shooting of a Mexican boy by a U.S. Border Patrol Agent. (AP Photo/J. Scott Applewhite) Credit: J. Scott Applewhite

Sixty feet and the U.S-Mexico border separated the unarmed, 15-year-old Mexican boy and the U.S. Border Patrol agent who killed him with a gunshot to the head early on a June evening in 2010.

U.S. officials chose not to prosecute Agent Jesus Mesa Jr., and the Obama administration refused a request to extradite him so that he could face criminal charges in Mexico. When the parents of Sergio Adrian Hernandez Guereca tried to sue Mesa in an American court for violating their sonโ€™s rights, federal judges dismissed their claims.

Sergioโ€™s family says he was messing around with his friends that day, playing a game in which they ran down the culvert from the Mexican side and up the American side to touch an 18-foot fence. Mesa arrived on a bicycle and detained one person while the others scampered back across the culvert. He then shot Sergio as the boy ran toward a pillar supporting an overhead rail bridge.

The Justice Department said Mesa was trying to stop โ€œsmugglers attempting an illegal border crossingโ€ and fired his gun after he came under a barrage of rocks. Mesa argues in his court filings that Sergio was among the rock throwers.

But Robert Hilliard, the familyโ€™s lawyer, said U.S. officials met privately with the parents to explain the decision not to prosecute Mesa and told them that their son had not thrown rocks. A cellphone video appears to show that Sergio was running and trying to hide before he was shot.

Had Sergio been shot a few feet to the north, he would have been on American soil and U.S. courts would be open to his family, Hilliard said. Thereโ€™s no dispute that Mesa was on the U.S. side of the border, he said.

If the family is kept out of court, Hilliard said, the Supreme Court will be saying โ€œthat 100 percent of the conduct of a domestic police officer in the United States is unconstrained by the U.S. Constitution.โ€ The family is seeking at least $10 million, Hilliard has said.

The Trump administration, like its predecessor, is arguing that the location of Hernandezโ€™s death, in Mexico, should be the end of the story.