NOHO (WABC) -- Police are investigating the death of a man who was allegedly harassing subway riders in NoHo before one passenger took matters into his own hands.
There are a lot of legal questions surrounding what happened on the F train on Monday afternoon because the man who may have been acting as a good Samaritan has not been charged.
Officials say the altercation happened around 2:30 p.m. on the train at the Broadway-Lafayette Street station.
A 24-year-old passenger stepped in to subdue a 30-year-old man who was acting erratically toward fellow riders.
It's not clear exactly how the confrontation unfolded, but it does not appear that any weapons were used.
Police say the 24-year-old man somehow knocked the 30-year-old man out. In the struggle, the 30-year-old lost consciousness and never regained it.
Authorities say he was taken to Lenox Hill Hospital where he was later pronounced dead.
So far, the NYPD has not released the names of either man in this case. The investigation seeks to answer all of the questions about what physically happened to the man who died and just how much of a threat he was.
According to police, the 24-year-old man's narrative is being corroborated by the other passengers on the train, who say that as he restrained the 30-year-old, he asked fellow passengers to call 911. The 24-year-old is a formerly enlisted Marine.
Police are awaiting the autopsy results on the 30-year-old.
Police say the man who died was a subway recidivist with 44 prior arrests for assault, disorderly conduct, and fare evasion.
Former NYPD Chief of Detectives Robert Boyce says the 24-year-old man may have indeed been defending himself and others from imminent harm, which sources say he claims, but there are other factors.
"How long was the actual hold... was he screaming let me go, let me go? All these things will go into the determination," Boyce said.
A determination of whether or not he made the right call, which ended up costing someone his life.
"The safest thing to do is to call 911 if you can down there, or find an officer nearby," Boyce said. "However, save those two instances, if there's an immediate need to help someone, you do it. Simple as that. So, he will have to articulate immediate need."
The man who attempted to subdue the alleged harasser was questioned by detectives and released. So far no charges have been filed.
Subway crime is down so far this year over last by about 6%, but Boyce noted that it's been impossible for the MTA and the city to ban recidivists and enforce a ban in the subway.
In the last year there has been an increased police presence on the subway, but it's not clear if there was an officer nearby when the 24-year-old stepped in and subdued the man.
ALSO READ | Family still hurting amid NYPD detective's death 33 years after botched robbery
* Get Eyewitness News Delivered
* Download the abc7NY app for breaking news alerts
Submit a tip or story idea to Eyewitness News