File - In this March 21, 2018 file photo, Border Patrol agent Lonnie Swartz, left, makes his way to the U.S. District Court building in downtown Tucson, Ariz., where opening arguments are scheduled to begin in the his murder trial in Tucson. Swartz, who was acquitted of second-degree murder in a case that ended in mistrial will be retried on lesser charges, the attorney for the family of the rock-throwing teen killed in a 2012 cross-border shooting said Friday, May 11, 2018. Attorney Luis Parra, of Nogales, Ariz., said in was in the federal courtroom in Tucson when U.S. prosecutors announced they would retry agent Lonnie Swartz for manslaughter. He said the new trial was set for Oct. 23 and is expected to last two months. (Ron Medvescek/Arizona Daily Star via AP, File)

PHOENIX - A U.S. Border Patrol agent who was acquitted of second-degree murder while jurors deadlocked on lesser counts will be retried in the cross-border shooting of a rock-throwing teen, prosecutors announced Friday in Arizona.

Agent Lonnie Swartz will be retried on voluntary and involuntary manslaughter charges, said Cosme Lopez, a spokesman for the federal court.

The prosecution did not plan to issue a statement on the decision, he said.

Luis Parra, an attorney for the family of 16-year-old Jose Antonio Elena Rodriguez, said he was with them in the courtroom in Tucson when the retrial decision was announced and they welcomed the news with joy.

Elena Rodriguez was shot in 2012 on a street just south of the border in Nogales.

"I'm relieved and very much appreciate the efforts" of the U.S. attorney's office, the boy's grandfather Jose Elena said.

Defence attorneys Sean Chapman and Jim Calle did not immediately return calls seeking comment.

Activists had called for the retrial while rallying outside the U.S. District Court building before the hearing in the first prosecution of a border agent involving a fatal shooting across the border.

"We are pleased for the family, that they will now have another chance at justice for Jose Antonio," said Lee Gelernt, an attorney for the American Civil Liberties Union in New York who is handling a civil case for the teen's mother. The lawsuit seeks monetary damages from Swartz.

Gelernt, deputy director of the group's Immigrants' Rights Project, said the decision to retry the criminal case should not affect the civil action.

The jury in the first trial declared a mistrial last month after they acquitted Swartz of murder and deadlocked on verdicts involving voluntary and involuntary manslaughter.

Elena Rodriguez was killed when Swartz fired 16 shots through a 20-foot (6-meter) fence on an embankment above Calle Internacional, a Nogales street lined with homes and small businesses.

Prosecutors acknowledged during the monthlong trial that the teen was lobbing rocks across the border during a drug smuggling attempt but said he did not deserve to die.

Defence attorneys countered that Swartz was justified in using lethal force against rock-throwers and shot from the U.S. side of the border in self-defence.

Court records say the new trial before Judge Raner Collins is set for Oct. 23 and expected to last four weeks.

The Border Patrol came under close scrutiny during the Obama administration amid allegations involving excessive use of force. Customs and Border Protection, its parent agency, reported 55 incidents in which employees used firearms from Oct. 1, 2011, to Sept. 30, 2012. The number of incidents fell to 17 for the same period five years later.

During closing arguments in the first trial, Assistant U.S. Attorney Wallace Heath Kleindienst said Swartz "was fed up with being rocked" after being targeted in at least six other attacks.

Defence attorney Chapman countered that there was "not a scintilla of evidence" that Swartz was angry or fed up. Chapman said Swartz shot because he was trying to protect himself and his fellow agents during a drug operation.

The trial played out as President Donald Trump called for National Guard troops to be sent to the Mexican border to free up Border Patrol agents to concentrate on stopping drugs and people from illegally entering the United States.

News from © The Associated Press, 2018