Eight US troops were charged on Wednesday in connection with the death of a fellow soldier allegedly abused in southern Afghanistan, the military said.
Five of the eight have been charged with negligent homicide, when death results from an act or failure to act of the accused.
Other charges include involuntary manslaughter, assault, maltreatment, reckless endangerment and dereliction of duty.
"Eight US soldiers deployed to southern Afghanistan were charged in connection with the death of a fellow soldier that occurred in October," said the US-led International Security Assistance Forces Regional Command South.
"The soldier was found in a guard tower with an apparent self-inflicted gunshot wound."
Those charged include a First Lieutenant, who faces eight counts of dereliction of duty, two Staff Sergeants, three Sergeants and two Specialists.
In October, The New York Times said investigators told Chen's parents three days after his death that they had not yet determined whether the shot to his head was self-inflicted or fired by someone else.
The Chens also said they were told that their son was subjected to physical abuse and ethnic slurs by superiors.
US troops have been fighting in Afghanistan since their 2001 invasion brought down the Taliban regime for refusing to surrender Osama bin Laden after the September 11, 2001 attacks on New York and Washington.
An ongoing drawdown will leave 68,000 US soldiers in Afghanistan by late 2012, ahead of the scheduled departure of all combat troops by late 2014.
Source: AFP South Asian Edition