Philadelphia train passengers who witnessed a man raping a woman and didn't intervene are unlikely to be charged, a spokesperson for the Delaware County district attorney's (DA) office said Wednesday.

Margie McAboy, a spokeswoman for the District Attorney in suburban Philadelphia where cops made the arrest, said that the investigation is still on, but there is "no expectation at this time that we will charge passengers," reported Associated News.

According to Fox News, Pennsylvania law does not allow for the prosecution of commuters who did not intervene on behalf of the woman, Delaware County District Attorney Jack Stollsteimer said Wednesday. He encouraged witnesses to share information with authorities about the incident, and said, "accordingly, any passenger who believes he or she may have observed the Oct. 13 event on the SEPTA (Southeastern Pennsylvania Transportation Authority) train should not fear prosecution."

On Oct. 13, over the course of a 40-minute train ride, a woman was repeatedly touched and groped despite trying to push the suspect, Fiston Ngoy, away. Cops said that the woman was riding on the Market-Frankford Line all by herself when the suspect came and sat next to her and they started talking.

Around 9.20 pm, minutes after the woman entered the train car, the suspect started touching her, making her to "continuously" push him away. Soon, he tried to touch her left breast and again, she pushed him away. After some time, Ngoy allegedly removed the victim's pants and lowered his trousers then he started thrusting her groin area for six minutes. Then a cop entered the train and pulled him off the woman "while (Ngoy was) actively raping the victim," read a complaint.

The suspect is charged with rape and related sexual assault offenses, and was being held on $180,000 bail.

It's not clear how many passengers witnessed the crime or recorded it, but police said that it appeared that some of them held their phones up in the direction of the attack and it looked like they were filming it.

In most US states, bystanders are under no legal obligation to help or intervene unless they have a "specific duty" to do so, such as cops, teacher, parents and caretakers, Kevin McMunigal, a former federal prosecutor and law professor at Case Western Reserve University, told BBC.

train-station-863337_960_720 Representation Image Woman waiting at train station Free-Photos/ Pixabay