Mental health experts say the soldier suspected of killing Afghan civilians could have post-traumatic stress disorder, or PTSD.The soldier's lawyer said his client had seen a fellow soldier's leg blown off a day before the killings, and had suffered a head injury and lost part of a foot during three earlier deployments to Iraq. The 38-year-old soldier, who has not been identified, left for Afghanistan in December.\This kind of a person would fit the profile for someone who might well have PTSD