Many people are wondering if a man could have been saved after being pushed onto the train tracks in front of an incoming New York City subway train.
Naeem Davis, 30, has prior arrests in New York and Pennsylvania, but mostly on minor charges.
He's already been arraigned and now sits in jail.
Police say more than a minute, possibly 90 seconds, passed before the train struck and killed Ki Suck Han, but none of the people standing on the platform stepped in to help the man out.
Channel 4 spoke with a local psychologist who said it takes a long time for the mind to process such disturbing things happening so quickly While many think it should be a simple choice to run and help the man, he said it's not that easy.
A photographer snapped a haunting picture within the minute 58-year-old Han was on the subway tracks, seconds before he was hit.
There were more than a dozen people on the platform, and while reports say they tried to stop the train, none of them tried to pull the man to safety.
Psychologist Dr. Gabriel Ybarra said one big factor is the bystander effect.
"A first reaction is to assume that other people are going to handle it," Ybarra said. "So you're standing at an intersection. Someone's having a heart attack. The assumption is someone else is going to jump in and take care of it."
Ybarra said the initial reaction is shock.
He said many of the people were likely going through their daily routine. When something so disturbing happens, bystanders are initially trying to assess what's happening. In this case, a bystander could have wondered if the man was going to be able to pull himself out, and what was the danger.
"That's quite a complex amount of information to process, so it becomes nearly paralyzing for some folks to act," Ybaarra said.
For those who do decide to act during a time of danger, Channel 4 crime and safety Analyst Ken Jefferson offers some advice.
"If you can get someone to help you so you all can help them, it's better when you have a team, if that's possible," Jefferson said. "If that's not available, you have to weigh it out as an individual."
Jefferson said first responders, law enforcement agents and military personnel have training, so they know how to jump in and act quickly in a dangerous situation.
But he says for the average person, that decision to act doesn't come instinctively.