(NBC News) - As a woman was raped on a public transit train in Philadelphia last week, riders held up their cellphones and pointed them in the direction of the sexual assault instead of calling 911, authorities said Monday.
Officials are investigating whether some bystanders actually filmed the attack, which happened Wednesday night while the woman was on the Southeastern Pennsylvania Transportation Authority (SEPTA) Market-Frankford line toward the town of Upper Darby.
“I can tell you that people were holding their phone up in the direction of this woman being attacked,” SEPTA Police Chief Thomas J. Nestel III said at a news conference.
A 35-year-old suspect, Fiston Ngoy, was arrested on rape and assault charges. Ngoy, who listed his last address as a homeless shelter, remains in custody on $180,000 bail. It's not clear if he has obtained an attorney or public defender.
Nestel said that other riders were on the train at the time of the assault but "there were very few notifications to the police."
There were no calls made to 911 in Philadelphia, according to the chief. Police are still waiting to see if 911 calls were made to Delaware County, which covers the last two stops on the train.
The attack wasn't reported until a transportation authority employee saw what was happening. Officials said at the news conference that officers responded within three minutes of the employee's report.
"What we want everyone to be is angry, disgusted and join us in being resolute to continue to make the system safe. We need help from the public to notify us when they see incidents that are occurring that are unusual," Nestel said.
"We want people to be our partners and to watch out for other riders," he continued.
Ngoy and the victim both got on the train at the same stop in North Philadelphia. An arrest affidavit states that Ngoy sat next to the woman about a minute after he boarded, shortly after 9:15 p.m., and harassed her for around 40 minutes as she repeatedly pushed him away.
Surveillance video shows the man ripping the woman's pants down just before 10 p.m., the affidavit states.
After the transit employee reported the attack, an officer waiting at the next station boarded the train, "saw what he believed was a criminal act occurring, ripped that man off of her and pulled him out onto the platform," Nestel said.
SEPTA called the incident a "horrendous criminal act" and said riders should contact police by calling 911 or pressing the emergency button on trains.
“There were other people on the train who witnessed this horrific act, and it may have been stopped sooner if a rider called 911,” the authority said.