Hasan's cousin, Nader Hasan, issued a statement late Thursday. "We are shocked and saddened by the terrible events at Fort Hood today. We send the families of the victims our most heartfelt sympathies," the statement read. "Nidal was an American citizen. He was born in Arlington, Va., and raised here in America. ... Our family loves America. We are proud of our country, and saddened by today's tragedy."
Nader Hasan said that she believed it was his upcoming deployment combined with the wartime horror stories he heard from his patients that set him off.
Hasan had reportedly recently hired an attorney to help him get out of the military.
According to the suspect's cousin, Hasan was also harassed after 9/11 because of his ethnicity, and was called a "camel jockey."
An Army official confirmed that Hasan would have been deployed to Afghanistan later this month. Sources told ABC News that this would have been his first deployment.
ABC News' Martha Raddatz contributed to this report