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

Karilyn Bales defended her husband, Staff Sgt. Robert Bales, in an interview with Matt Lauer for NBC’s “Today” show that aired this morning.

The Washington state woman said her husband joined the Army after the terror attacks of Sept. 11, 2001, to “protect his family, friends and country. He wanted to do his part,” and added that her husband is “very brave, very courageous.”

Officials say Bales wandered off base in southern Afghanistan earlier this month and killed eight Afghan adults and nine children.

The wife of the Joint Base Lewis-McChord soldier 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.

She said he never had nightmares or other signs of PTSD and she feels like he was mentally fit when he was deployed. She also said he never told her about a traumatic brain injury he suffered while in Iraq, until he returned home.