PHOENIX (AP) — A judge in Arizona has declared a mistrial in the case of a U.S. Border Patrol agent after a jury acquitted him of a second-degree murder charge in the killing of a teenager but deadlocked on lesser counts of manslaughter.

The mistrial was called Monday in Tucson by Judge Raner Collins after jurors acquitted Agent Lonnie Swartz on the murder charge in the cross-border shooting of a teenager in Mexico who was throwing rocks at authorities during a drug smuggling attempt.

The U.S. Attorney's Office says it's evaluating whether to pursue a retrial on the manslaughter charges in the 2012 death of Jose Antonio Elena Rodriguez.

Prosecutors acknowledged Elena Rodriguez was lobbing rocks during a drug smuggling attempt but said he didn't deserve to die.

Defense attorneys countered Swartz shot from the U.S. side of the border in self-defense.