A military jury has sentenced a U.S. soldier who massacred 16 Afghan civilians last year to life in prison without a chance of parole.

The decision came Friday in the case against Staff Sgt. Robert Bales who pleaded guilty in June in a deal to avoid the death penalty for one of the worst atrocities of the Iraq and Afghanistan wars.

Bales took the witness stand Thursday and apologized for the pre-dawn attack in March 2012, describing it as an act of cowardice.

Bales, a father of two from Lake Tapps, Washington, was serving his fourth combat deployment when he left his outpost at Camp Belambay, in Kandahar province, in the middle of the night to attack two villages.