A security guard at a gated community in Mount Sinai is facing assault charges after beating up a man there, police say.

John Ruggiero, 50, a former New York City police officer, is accused of assaulting a 68-year-old man at The Ranches at Mount Sinai around 3 p.m. on Aug. 14. The 68-year-old was seriously injured, and Ruggiero was also treated at the hospital for his injuries, according to police.

Police say the 68-year-old man wanted to see a friend and Ruggiero would not allow it. The men exchanged words and a physical altercation ensued, the authorities say.

Prosecutors say Ruggiero punched the other man in the face several times – even after the victim was on the ground.

"He hit me first," Ruggiero said as he was taken out of the precinct to head to court on Thursday for his arraignment. Ruggiero's attorney says the alleged victim is the one who started the fight.

The 68-year-old suffered multiple serious injuries, including facial fractures and a brain bleed, according to the authorities. He was rushed to the hospital and remains there, unconscious and on a respirator.

John Parks, who identified himself as a friend of the 68-year-old, says that man's name is Jack Carter. Parks says he arrived at the scene right after the incident and was horrified by what he saw.

"He was in bad shape," Parks says.

Ruggiero, of Port Jefferson Station, was arraigned in Central Islip Thursday afternoon. He has been released after posting $7,500 bond.