PHILADELPHIA (AP) — Prosecutors pursuing the case against a man accused of raping a woman on a commuter train last week don’t anticipate charging fellow passengers for not intervening, a spokesperson for the suburban Philadelphia district attorney said.

“It’s still an open investigation, but there is no expectation at this time that we will charge passengers,” said Margie McAboy, spokeswoman for the Delaware County District Attorney’s office.

In an emailed statement, District Attorney Jack Stollsteimer said prosecutors want witnesses to come forward, rather than fearing prosecution, and said, “Pennsylvania law does not allow for the prosecution of a passenger who may have witnessed a crime.”

Authorities continue to investigate the Oct. 13 attack, where a woman was repeatedly touched and groped over the course of a 40-minute ride despite trying to push 35-year-old Fiston Ngoy away, according to an arrest affidavit that detailed the surveillance footage from the train.

Investigators say Ngoy ripped the woman’s pants off and proceeded to rape her for somewhere between six and eight minutes before officers boarded the train and detained him.

Police declined to say how many passengers may have witnessed the assault, but have said it appeared that some held their phones up in the direction of the assault seemingly to film the attack. Police have also declined to say whether investigators have found any photos or videos of the attack posted online.

Requests by The Associated Press for surveillance video from the Oct. 13 attack on the Market-Frankford line have been denied, citing the ongoing criminal investigation. It remains unclear whether passengers actually witnessed or recorded what happened on the Southeastern Pennsylvania Transportation Authority train.

SEPTA spokesman Andrew Busch said Wednesday that at points during the rape, there were passengers standing or sitting nearby, though he couldn’t guess whether any understood the serious nature of the situation.

“Chief (Thomas) Nestel made his best estimate that 10 people were walking through, sitting or standing near where the attack was occurring at points throughout the assault,” Busch said. “Our hope is that people will realize when they see this type of activity, whether they fully understand it or not, that they will push the emergency call button or call the police. There really was no way to not see it even if they didn’t fully understand.”

Legal experts said unrelated passengers don’t have a legal duty to intervene under Pennsylvania law.

“Unless they have a legal duty to intervene, like a parent for their child, a person cannot be prosecuted for sitting back and doing nothing,” said Jules Epstein, a law professor and director of advocacy programs at Temple University Beasley School of Law.

“Doing nothing may be morally wrong, but in Pennsylvania, without that special duty relationship, it is not legally wrong,” Epstein said.

Busch said the employee who called the police, entered the train car after the assault had begun, but his call meant police had an opportunity to arrest Ngoy.

“Without that call, the suspect might have been able to just walk off the train and we would still be looking for him,” Busch said.

SEPTA’s police chief, Nestel has said Philadelphia 911 did not receive any calls about the attack. He said Monday operators at Delaware County 911 were still researching whether it received calls.

Ngoy is charged with rape and related sexual assault offenses. He was being held on $180,000 bail, awaiting an initial appearance scheduled for Oct. 25. Attorney Mary Elizabeth Welch confirmed the Delaware County Public Defender’s office is representing Ngoy, but said she could not comment on the case Wednesday.

Court records show Ngoy has a history of arrests and convictions under at least three names in Washington D.C., Philadelphia and suburban Southeastern Pennsylvania counties including public intoxication, defecating or urinating in public, public disturbance and other charges.

In D.C., Ngoy pleaded guilty to misdemeanor sexual abuse in November 2017 under the name Jack Falcon, after police said he groped two women on the street near a homeless shelter where he was staying.