A 63-year-old man was found face-down in a pool of his own blood in a fatal stabbing at a Queens psychiatric facility Monday morning, cops and sources said.

Ronald Giacopelli, 63, was discovered around 10:35 a.m. bleeding out on the floor of a room inside Hazel House — a residential facility on the campus of the state-run Creedmoor Psychiatric Center on Winchester Boulevard in Bellrose Manor — according to police and law enforcement sources.

He had suffered multiple stab wounds to the back of his neck and his lower back, authorities said. 

David Zheng, 23, was taken into custody in connection to the slaying — and claimed he didn’t remember anything about the deadly violence, cops and sources said. 

He was charged with second-degree murder, tampering with physical evidence and criminal possession of a weapon, authorities said Tuesday. 

Both Giacopelli and Zheng were residents at the facility, sources said. 

No charges were immediately filed, cops said. 

Police recovered a knife in the room where the slaying took place, which is also where the younger man was staying, according to the sources.

“OMH was alerted of a fatal stabbing that occurred earlier today at Hazel House, a licensed residential program operated by a community service provider on the campus of the Creedmoor Psychiatric Center,” a spokesperson for the state’s Office of Mental Health said in a statement. “We are fully cooperating with the NYPD’s investigation and will review the circumstances that lead to this tragic event.”

Hazel House is a 52-bed licensed residential program operated by Transitional Services for New York.