NEW YORK, July 2 (Reuters) - Kari Bales, the wife of a U.S. Army staff sergeant charged with killing 16 villagers in Afghanistan in March, said on Monday she continues to believe her husband is innocent and that "I don't think that anyone really knows what happened."

But she also said she has not asked Robert Bales, her husband of seven years who is charged by the U.S. military with 16 counts of murder in the March 11 mass shooting, what happened on that day.

"I just don't need to ask him. I know my husband and it's not a question I really need to ask. I know him," she told the "CBS This Morning" program.

Robert Bales, a decorated veteran of four combat tours in Iraq and Afghanistan, is accused of walking off his base under cover of darkness and opening fire on civilians in their homes in at least two villages. The incident in Afghanistan's Kandahar province eroded already-strained U.S.-Afghanistan relations.

When she first learned of the incident, Bales said: "I was completely shocked and didn't believe what they were telling me, couldn't believe that it happened, didn't believe my husband was involved at all."

Asked if she continued to believe her husband was not involved in the massacre, Bales responded: "I still do not."

"I want to know what happened. I don't know what happened and I don't think that anyone really knows what happened," she said.

Bales faces the death penalty if convicted, as premeditated murder is a capital offense under U.S. military law. A minimum sentence would be life in prison with eligibility for parole, according to the military.

Kari Bales said when she talked to her husband two days before the shooting, they did not discuss anything out of the ordinary, and that he had wanted to come home to see their two children.

"He wanted to be home. He wanted to be with us. Deployments are always hard. This was our fourth one," she said.

(Reporting by Joseph O'Leary; additional reporting by Eric Beech; Editing by Will Dunham)