Police say a man came up behind the victim, 76-year-old Ross Falzone, and pushed him down the 18th Street station stairs just after 9:30 p.m. on Thursday.
First responding officers found the Falzone unconscious and unresponsive. Officials say he suffered a traumatic brain injury, a fractured spine and a fractured rib and was pronounced dead at Bellevue Hospital just before 3 a.m. on Friday.
Police say the shoving appeared to be unprovoked, and the death is being investigated a homicide.
They also revealed that the person of interest had been picked up by police hours earlier outside and East Side police precinct.
Officers encountered the man acting erratically outside the 17th Precinct stationhouse on East 51st Street at around 3:30 p.m.
Police say he pulled a stick from the garbage and held it as he approached the officers.
One officer defused the situation, an interaction captured on his body-worn camera and reviewed by police officials, and took the man to Bellevue Hospital in a police cruiser, arriving at the hospital at 3:39 p.m.
He underwent a psychiatric evaluation at the hospital and was released later that afternoon.
Detectives say that same man then shoved Falzone to his death about five hours after his release from Bellevue.
According to authorities, Falzone lived on the Upper West Size.
The person of interest, described as a man in his 20s or 30s, wearing a black shirt, black shorts and a red and black fanny pack, was taken back into custody for the subway shove on Friday at Penn Station, on the northbound C and E line platform, around 3:30 p.m.
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