Dierks BentleyWhen Dierks Bentley performed at the Fort Hood Army base on Independence Day earlier this year, he had no way of knowing that the meet-and-greet picture he would take with a soft-spoken female police officer would be posted five months later alongside national news headlines hailing Sgt. Kimberly Munley as a hero. Sgt. Munley, of course, is the 34-year-old police officer who would take down a crazed shooter in the heat of a horrific massacre Nov. 5 at the Killeen, Texas, military base, killing 13 people.

Even before Dierks took the picture with Sgt. Munley, he somehow sensed there was something about the petite young officer that stood out as she watched him greet fans.

"She was on the police force and was off to the side ... but I could tell she was a fan," Dierks tells PEOPLE. He remembers clearly how she waited quietly until fans were through taking pictures and getting autographs, and then approached him for a picture.

When Dierks learned that it Sgt. Munley who'd felled the gunman during the shootout, he managed to get a call through to her the very next morning.

"I said I was honored to have my picture with her, and that my band and I were all thinking of her and praying for the folks on the base," Dierks says. " I told her, 'We are all just really thankful to you. She was quiet, and she's just a humble person and said she was just doing what she does. She would say she's just out there doing her job, but it's a pretty amazing job she did. It's pretty impressive."

Despite Sgt. Munley's injuries and the horror of what she'd been through, Dierks says that she's in good spirits.

"I can't imagine what that experience was like, but she said she's OK," he reports. "She said she lost a lot of blood, but it sounded like she's on the road to recovery."

Dierks is anxious now to return to Fort Hood to pay what will most certainly be an emotional visit to Sgt. Munley and the base.

"I told her that she was in our prayers, and we wanted her to get a speedy recovery, and that we'll get down there when all the hoopla is over," Dierks tells ABC News. "I feel like I should be asking for the meet-and-greet now because she's a hero. I'm just a country singer. She's a national hero.

"God, these families -- there is a reason why they call them Army strong," Dierks notes. "There's strong -- and then there's Army strong. They have to deal with their friends, husbands, sons, daughters putting themselves in harm's way far away and now to have that worry in their own community, where they should feel they are the safest? But these are the strongest people. It's a really tight-knit group, and they lift each other up when they are down."