PHOENIX — Prosecutors in the murder case against a Border Patrol agent won’t dispute that the teen he shot and killed through the border fence was throwing rocks — and apparently trying to assist drug smugglers.

In new filings in federal court, Assistant U.S. Attorney Wallace Kleindienst told Judge Raner Collins that the government “will not dispute” at trial that Jose Antonio Elena Rodriguez “was one of three individuals who ... was throwing rocks over the fence.”

Kleindienst said prosecutors also will not contest that the rock throwing by the 16-year-old was apparently done to help two people on top of the fence “who were trying to successfully drop down onto the Mexican side of the border after smuggling two bundles of marijuana into the United States.”

But he said the question of whether Elena Rodriguez was employed by a drug cartel “is simply unknown.”

The concessions by the government are significant because it means attorneys for Lonnie Swartz will be able to present that information to a jury at the criminal trial set to begin in October.

Defense attorney Sean Chapman, in his own legal filings, said that information will help jurors understand the situation when Swartz admittedly fired through the fence, hitting Elena Rodriguez, who was on the Mexican side of the border, in the back at least 10 times.

Chapman contends that will show Swartz did not act “with malice aforethought,” the legal standard to gain a conviction on charges of second-degree murder.

But Kleindienst is arguing that, rocks or no rocks, it does not affect the case he is preparing against Swartz.

“This is not a drug trafficking case,” he wrote. “This is simply a case about whether Elena Rodriguez presented a threat of serious bodily injury or death (to Swartz) regardless of his motives.”

In some ways, the government is in no position to deny that there were rocks.

At a hearing earlier this month, prosecutors showed the judge a video that is a combination of actual security camera footage and incident reconstruction, including rocks being thrown. They want his permission to show it at the trial because it provides some evidence that Swartz fired at least 13 times, including stopping to reload.

Chapman is arguing against its admission.

The government’s concession about what the teen was doing shortly before he was killed comes amid another series of motions about what jurors can see and be told. That includes a bid by Chapman to have a witness tell jurors about drug smuggling, both overall and in the Nogales area.

The defense attorney said the practices of smugglers were known to Swartz and other agents who work the area. Chapman said that shows that Swartz knew this was an “extremely dangerous” area of the border.

“Drug smugglers tend to be more desperate, more dangerous, and more frequently attempt to assault agents to avoid apprehension,” the attorney said. “They are most likely to throw rocks and carry weapons.”

In fact, Chapman said, prosecutors have disclosed that one of the smugglers on top of the fence when the shooting occurred was seen to have a long double-edged knife in his back pocket.

Chapman also wants to show jurors various Border Patrol training videos that “emphasize to agents how dangerous rocks can be.”

“The jury is not only going to need to understand what occurred in this case but why Agent Swartz reacted as he did, in order to assess Agent Swartz’s state of mind,” the defense attorney told the judge in his legal filings.

Kleindienst agreed that jurors have to decide if Swartz’s actions “were reasonable and necessary under the circumstances.” He conceded that the agent’s state of mind is relevant, including whether the rocks constituted a “threat of imminent serious bodily injury or death.”

But the prosecutor said what Chapman wants to introduce is “evidence patently calculated to inflame the jury.”

The same is true, Kleindienst said, about what the victim was doing at the time of the shooting.

“This is simply a case about whether Elena Rodriguez presented a threat of serious bodily injury or death by throwing rocks into the United States regardless of his motives,” the prosecutor wrote.

In a statement last month, attorney Luis Fernando Parra, who represents the 16-year-old’s family, denied allegations that the teen was involved in any kind of drug smuggling.

“This is an effort to deflect attention from an unlawful killing by the U.S. Border Patrol,” he said.

The family has filed a separate wrongful death civil case against Swartz. That case remains on hold until the U.S. Supreme Court rules whether survivors of people who were not in the country when they were killed can file suit in federal courts here.