A federal grand jury Wednesday charged U.S. Border Patrol Agent Lonnie Swartz with second-degree murder in the 2012 cross-border shooting death of a Mexican teenager. An attorney for the mother of 16-year-old Jose Antonio Elena Rodriguez confirmed the news of indictment to the Associated Press.

Border Patrol officials have said Elena Rodriguez was among a group throwing rocks at agents from across the border at Nogales, Arizona. But the boy's family contends he was walking home from a basketball game with friends and did not participate in the assault.

"The Elena Rodriguez Family is grateful to the DOJ [U.S. Department of Justice] for this first step in the pursuit of justice, and remain steadfast in their resolve to seek full transparency from the U.S. Border Patrol on behalf of Jose Antonio," Luis Parra, the family attorney, told the AP. Swartz shot the teen 10 times, according to an autopsy report.

Sean Chapman, Swartz's attorney, told the Arizona Daily Star in Tucson that his client is likely to plead not guilty at an Oct. 9 arraignment. Swartz is also facing a federal civil rights lawsuit in Elena Rodriguez’s Oct. 10, 2012, death.

The Elena Rodriguez case sparked outrage over the Border Patrol’s use of force and other alleged abuses against foreigners and immigrants detained at the U.S. border with Mexico. Border Patrol officials have said agents are allowed to use force against rock throwers because their lives are at risk.

The agency has also faced criticism over its treatment of unauthorized immigrants and border crossers at detention centers in the U.S. Forty percent of Mexican migrants deported from the U.S. from 2007 through 2012 said agents violated their human rights while they were detained, according to a report released this week by the Kino Border Initiative and the Jesuit Conferences of Canada and the United States.

The U.S. Commission on Civil Rights last week criticized the Department of Homeland Security, which runs the Border Patrol, for not complying with detention standards “intended to promote the humane treatment of detainees.”