SEATAC, Wash.: The wife of a U.S. soldier accused of killing 17 Afghan civilians says her husband showed no signs of post-traumatic stress disorder before he deployed, and she doesn’t feel like she’ll ever believe he was involved in the killings.

“I don’t know a lot about the symptoms of PTSD, so I wouldn’t know,” Karilyn Bales told NBC’s Today show. “He doesn’t have nightmares, you know, things like that. No dreams.”

She defended her husband, Staff Sgt. Robert Bales, in a weekend interview with Matt Lauer that aired on Monday. Officials allege that Bales left his base in southern Afghanistan on March 11 and killed eight Afghan adults and nine children.

Bales’ wife said the accusations are “unbelievable to me.”

“He loves children. He’s like a big kid himself,” she said. “I have no idea what happened, but he would not ... he loves children, and he would not do that.”

He was formally charged Friday with 17 counts of premeditated murder and other crimes, and is being held at a U.S. military prison at Fort Leavenworth, Kan.

Bales was on his fourth tour of duty in a war zone, having served three tours in Iraq, where he suffered a head injury and a foot injury.

His civilian attorney, John Henry Browne, has said the soldier and his family had thought he was done fighting.

“It was a big shock because we weren’t on the schedule to be deployed again, to be honest with you. He didn’t want to miss out on any more of his kids’ life,” Karilyn Bales told Today.