Lonnie Swartz, left, did not act recklessly with disregard for human life, his lawyers hope to show.

Prosecutors in the rare second-degree murder trial of a Border Patrol agent in a fatal cross-border shooting of a teenager in Nogales, Sonora have opened their case saying the 16-year-old didn't deserve to die for throwing rocks over the international boundary.

Jose Antonio Elena Rodriguez was throwing rocks over the fence to help drug smugglers by serving as a distraction as they returned to Mexico after leaving backpacks of marijuana in the U.S., Asst. U.S. Attorney Mary Sue Feldmeier acknowledged to jurors in her opening statement Wednesday. 

But she says the teen didn't deserve the death penalty for his crime and the day he was killed Border Patrol Agent Lonnie Swartz "became the judge, the jury and the executioner."

Feldemeier has also told the newly selected jury that they are not trying an immigration or drug smuggling case, but a second-degree murder case.

Meanwhile. the defense lawyer said the officer was justified in using deadly force against rock throwers working with drug smugglers.

Attorney Sean Chapman told the jurors in his opening statement that Swartz was protecting himself and other agents when he fired across the international line.

Chapman says Elena Rodriguez put himself in danger by throwing rocks at the agents.

He said rocks thrown that night by several people hit another agent in the foot and also struck a police dog.

Swartz has pleaded not guilty in the 2012 shooting and is free on his own recognizance.

Elena Rodriguez was shot on a street in Nogales, Mexico, across the border from Nogales, Arizona.

An autopsy showed the unarmed teen was shot 10 times, mostly from behind.