By Michelle Richmond and Barbara Starr

In order to avoid the death penalty, U.S. Army Staff Sgt. Robert Bales intends to plead guilty in the killing of 16 Afghan villagers, his lawyer said Wednesday.

A plea deal - which Bales' lawyer John Henry Browne told CNN about by text message, as he was meeting with his client - must be approved by a judge and a commanding general.

In addition to those killed, six Afghans were wounded in the March 2012 attack near a small U.S. base in Afghanistan's Kandahar province.