U.S. investigators in Nogales, Sonora, have visited the site where a Sonora 16-year-old was fatally shot in 2012 by a Border Patrol agent.

Cosme Lopez, spokesman for the U.S. Attorney’s Office in Phoenix, confirmed that officials from the office were in Nogales on Tuesday but wouldn’t comment on whether there’s an ongoing case. The Nogales International published photos of U.S. assistant attorneys at the spot where the body of Jose Antonio Elena Rodriguez was found across from the border fence.

Elena Rodriguez was shot multiple times in the back on Oct. 10, 2012. His body was found about 40 feet from the border fence near the downtown port of entry in Nogales. The Border Patrol says agents were responding to rock throwers in the area when they fired, but a witness said the teen was just walking.

Ana Ceja, Elena Rodriguez’s aunt, said streets were closed off until after 3 p.m. and that investigators were taking measurements and examining bullet holes circled on the wall of a doctor’s office above the spot where the body was found.

An FBI investigation is still open, a spokesman for the agency said Monday.

Last month, Elena Rodriguez’s mother filed a civil-rights lawsuit in federal court. Attorneys have requested the agent’s name because it is needed for the complaint to move forward.

Nogales, Arizona, police officers went to the scene the night Elena Rodriguez died, but John Zuniga, one of the officers, did not take the name of the Border Patrol agent who fired the shots because he did not know he had to, he wrote in an Aug. 14, 2014, memo to Nogales Police Chief Derek Amson.

In the memo, written after attorneys for the teen’s family subpoenaed the city of Nogales for the agent’s name, Zuniga said a Customs and Border Protection officer who asked about his police dog after the shooting told him the agent involved had been working at the Grand Port of Entry. Zuniga told his boss the agent’s last name as reported by the CBP officer, but the Star is not publishing that name because it has not been confirmed he was the shooter.

Sean Chapman, an attorney representing the Border Patrol agent, wouldn’t say whether the CPB officer had the correct name.

Getting the name of the agent or agents involved is an important step for Elena Rodriguez’s family, said Luis Parra, one of the attorneys representing the family.

“From the beginning, what they wanted was transparency, to know what disciplinary action, if any, was going to be taken,” Parra said.

The Border Patrol has been increasingly scrutinized for its use of force and lack of transparency, including not releasing the names of agents involved in fatal shootings.

Since 2010, nearly 30 people have died in Border Patrol-related shootings — at least six in cross-border incidents.

A quarter of the 28 deaths were “highly suspect,” James F. Tomsheck, CBP’s former head of internal affairs, recently told the Center for Investigative Reporting. He was removed from the internal-affairs office in June.

Tomsheck told the Berkeley, California-based nonprofit news agency that Border Patrol officials have consistently tried to change or distort facts to make fatal shootings by agents appear to be “a good shoot” and cover up any wrongdoing, the center reported.

He also told CBS News this week that he was “familiar with several incidents where the persons appeared to be fleeing and were shot in the back or the side at some distance from the Border Patrol agent when the shots were fired.”

That doesn’t add up, said Art del Cueto, president of the local Border Patrol union.

“He was the head of internal affairs. If that was going on, why didn’t he do something about it?” del Cueto asked.

In July, several agents at the scene of a fatal shooting of a suspected drug smuggler in Green Valley seemed unaware of how an officer-involved shooting was investigated, a Pima County sheriff’s deputy wrote. They didn’t understand why they had to turn over evidence and be subjected to investigators’ questions.

Border Patrol leaders have called for more transparency. In May, the agency released a previously secret report that documented some agents’ misuse of their firearms, including placing themselves in the path of moving cars, and that “some cases suggest frustration is a factor motivating agents to shoot at rock throwers.”

It also questioned investigations. “It is not clear that CBP consistently and thoroughly reviews all use of deadly force incidents,” it read.

Earlier this year, it released its use-of-force policy and issued a directive that reminds agents that — in accordance with current policy — they should not discharge their weapons at a moving vehicle unless they have a reasonable belief that deadly force is being used against them or another person.

Border Patrol Chief Michael Fisher also repeated that agents should avoid putting themselves in positions where they have no alternative than to use deadly force against cross-border rock throwers.

Rock throwers have pelted agents 1,713 times since 2010, Fisher has said. Agents fired their service weapons 43 times in those incidents, killing 10 people.

Contact reporter Perla Trevizo at ptrevizo@tucson.com or 573-4210. On Twitter: @Perla Trevizo