The D.C. Office of the Chief Medical Examiner publicly released the manner for graduate student Patrick Casey’s death as a homicide Wednesday.

The cause of the 33-year-old Afghanistan war veteran’s death was blunt impact trauma resulting in injuries to his head, Beverly Fields, chief of staff at the medical examiner’s office, said.

Examiners conducted an autopsy Sept. 29, but Fields declined to release results until Wednesday afternoon, saying the office was waiting to inform Casey’s family.

Casey, who was earning a master’s at the Elliott School of International Affairs, was legally declared dead Sept. 29, two days after he was pronounced brain dead.

The Metropolitan Police Department initially began looking into Casey’s death as a felony assault but later shifted to a homicide investigation.

Casey was “irritating” other patrons at a McDonald’s restaurant near campus, but not directly instigating a fight, early Sept. 23, MPD spokeswoman Gwendolyn Crump said.

The verbal fight escalated into a physical confrontation. Crump said there are “indications” that Casey was drinking that night.

Fields declined to comment further on autopsy results beyond the cause and manner of Casey’s death.

“We have indications Mr. Casey did push or throw a subject to the ground immediately preceding his being pushed or punched, which resulted in his falling to the ground and striking his head,” Crump said Monday. “There are currently no charges being filed as the investigation continues. The determination as to whether or not anyone is charged will be made after the investigation has been completed.”

Friends and family said Casey was a “gentle giant.” The 6-foot-4-inch veteran with an infectious smile had a football player’s build, but was a “big teddy bear,” they said.

The University will hold a memorial service for the Clifton, N.Y. native at 6 p.m. Thursday at Veterans Park at 22nd and G streets.