Witness says Jordan Neely started making death threats against passengers before Daniel Penny engaged him

She alleged that Penny, a former Marine, refrained from jumping in and using force to subdue Neely until there was a threat of violence.

The 66-year-old woman, who chose to remain anonymous, told the New York Post that Neely's erratic behavior soon took a turn for the worse and he began shouting at other passengers.

"He said, 'I don't care. I'll take a bullet, I'll go to jail' because he would kill people on the train," she recalled. "He said, 'I would kill a motherf*cker. I don't care. I'll take a bullet. I'll go to jail'."

She went on to explain how Penny reacted in the situation, noting that he "did not stand up, did not engage with the gentleman. He said not a word. It was all Mr. Neely that was … threatening the passengers."

The woman said she had gone back to Penny and said thank you following the altercation, adding that she hoped he "has a great lawyer."

"I'm praying for him," she told the Post, "and I pray that he gets treated fairly."

New York's medical examiner determined that Neely died from "compression of neck," and stated that his death was the result of "homicide." Penny was subsequently charged with second-degree manslaughter and could face up to fifteen years in prison if convicted. Penny turned himself in on Friday, and was released on bond, according to ABC News.

The ex-Marine's lawyers have argued that he was acting in self-defense, and didn't mean to kill Neely. Video of the incident showed that he put Neely in the "recovery position," in an attempt to ensure that he would be okay.