request to overturn Bales' conviction or modify his sentence, an Army spokesman said Friday. That automatically sends the case to the Army Court of Criminal Appeal, where it might be considered again by military judges one day.

Bales, an Ohio native and father of two from Lake Tapps, Washington state, shot 22 people in all, including 17 women and children, during pre-dawn raids on two villages in Kandahar Province in March 2012. The massacre prompted such angry protests that the U.S. temporarily halted combat operations, and it was three weeks before Army investigators could reach the crime scene.

Bales pleaded guilty in a deal to avoid the death penalty, and he apologized in a statement at his sentencing in 2013. He described the perpetual rage he felt, his heavy drinkingand reliance on sleeping pills, and his steroid use. He also said he couldn't explain what he did, a sentiment he repeated in the letter.

"Over my past two years of incarceration, I have come to understand there isn't a why; there is only pain," he wrote.

The letter provides additional detaila about the paranoia Bales says he felt during his last deployment and the toll financial worries were taking on him.

"I didn't want to make a decision on the ground and lose one of my guys," he wrote. "Normally that would be a good thing, but now I know it made me paranoid and ineffective."

Over his combat tours he came to hate "everyone who isn't American," he wrote, and he became suspicious of local residents who might be supportive