The gunman who killed five police officers in Dallas, identified as Micah Xavier Johnson, displayed a noticeable change in behavior after being discharged from the U.S. Army in 2015, the shooter’s parents told TheBlaze in an exclusive interview set to air later this week.

Video: Dallas gunman’s neighbor says killer seemed level-headed.

The family of Dallas shooter Micah Johnson speaks out for the first time since the attack that left five police officers dead.

After refusing to speak to the media, the family reached out personally to TheBlaze’s Lawrence Jones after seeing him on television. On Sunday, Jones sat down with Johnson’s parents and stepmother at the mother’s Mesquite, Texas, home where investigators said they found rifles, ammunition, “bomb-making materials†and a journal of combat tactics.

Delphine Johnson, the gunman’s mother, said she watched her son transform from a fun-loving extrovert into a “hermit†after his military service, which spanned roughly six years and included a seven-month deployment to Afghanistan. While the parents couldn’t recall their son mentioning any particular incident that may have been traumatic during his time as a U.S. Army reservist, they agreed something had changed.

Growing up as a kid, Johnson actually wanted to be a police officer and later became “gung-ho†about enlisting the military, the mother recalled.

Investigators leave the home of Micah Johnson in the Dallas suburb of Mesquite, Texas, Friday, July 8, 2016. A Texas law enforcement official identified Micah Johnson, 25, as the sniper that opened fire on police officers in the heart of Dallas during protests over two recent fatal police shootings of black men. (AP Photo/LM Otero)

Investigators leave the home of Micah Johnson in the Dallas suburb of Mesquite, Texas, Friday, July 8, 2016. A Texas law enforcement official identified Micah Johnson, 25, as the shooter that opened fire on police officers in the heart of Dallas during protests over two recent fatal police shootings of black men. (AP Photo/LM Otero)

“He loved his country,†she said. “He wanted to protect his country.â€

But Johnson’s idealism seemed to fade away over time, and was replaced by disappointment and resentment toward the government.

“The military was not what Micah thought it would be,†Delphine said. “He was very disappointed, very disappointed. But it may be that the ideal that he thought of our government, what he thought the military represented, it just didn’t live up to his expectations.â€