A federal judge says a Border Patrol agent charged in the shooting death of a Mexican teen in 2012 cannot be cross-examined about his military record.

The U.S. District Court judge ruled Lonnie Ray Swartz cannot be questioned over his Army and service personnel records, which are more than 10 years old.

This was after the U.S. Attorney's Office for Arizona filed a motion objecting to a defense move to exclude those records. They include a desertion arrest.

Swartz has pleaded not guilty to one charge of second-degree murder in the death of 16-year-old Jose Antonio Elena Rodriguez.

Swartz is accused of firing through a border fence from Nogales, Arizona, into Nogales, Mexico, and killing the teenager.