Updated

The Mexican government is asking a U.S. appeals court to let a Mexican teenager's parents sue a Border Patrol agent who fatally shot their son from across the border.

The arguments are in one of three "friend of the court" briefs filed this month with the 5th U.S. Circuit Court of Appeals, which is hearing the case of Sergio Hernandez for the second time Wednesday.

All three briefs ask the court to overturn a district judge's ruling that Hernandez's family cannot sue agent Jesus Mesa Jr. over the shooting in 2010.

A divided three-judge panel ruled June 30 that the family could sue Mesa. He asked all 15 judges to look at the case, and they agreed.

Lawyers filing "friend of the court" briefs rarely join oral arguments.