FOXBORO, Mass. (WPRI) — The Office of Massachusetts’ Chief Medical Examiner has ruled the September death of a longtime New England Patriots fan a homicide, according to a release from Norfolk District Attorney Michael W. Morrissey.

Dale Mooney, a 53-year-old from Newmarket, New Hampshire, collapsed at Gillette Stadium on Sept. 17 after a physical altercation during a game between the Patriots and the Dolphins. He was pronounced dead at the hospital.

While an initial autopsy indicated that Mooney’s death was the result of a medical issue, the final results from the medical examiner determined the altercation caused Mooney, who had severe atherosclerotic cardiovascular disease, to experience a “probable cardiac dysrhythmia” that led to his death.

John Vieira, 59, and Justin Mitchell, 39, both of Warwick, have been charged with assault and disorderly conduct, as Morrissey ruled that the existing evidence does not provide a sufficient basis for homicide charges.

The two were arrested by Foxboro police on Oct. 6, according to a criminal complaint filed in Wrentham District Court.

“We thank the members of the public who made their private videos of the altercation available for our review, and the investigators at the Foxborough Police Department, for their help in establishing a clear picture of these tragic events,” Morrissey said in the release.

Both men are scheduled to be arraigned next month.