The women are often brought in through New York and taken in vans and taxis along Interstate 95 to New Jersey and Pennsylvania and points farther south and west.
Then they are delivered to massage parlors, the kind that clients talk about on lewd websites, and forced into sex work that doesn't end.
Most come from Asia, frequently China and South Korea, lured with false promises of visas, housing, or high salaries, but manipulated into debt to their traffickers that keeps them captive.
That's according to a new report on human trafficking that says at least 9,000 massage businesses nationwide are suspected to be fronts for sex trafficking. Of those, about 260 are located in Pennsylvania and 370 in New Jersey, ranking them seventh and fifth among the states with the most massage-parlor trafficking, thanks in part to their location along the northeast corridor, according to Polaris, a nonprofit that operates the National Human Trafficking Resource Center hotline and published the report this month.
"In Philly, there's some of the more intimidating [businesses] we've seen in the country," said Rochelle Keyhan, strategic initiative director at Polaris. That means massage parlors with steel bars on the windows, multiple security cameras outside, bolted front doors, and back-alley entrances — some right in Center City.
Dozens of massage businesses in the Philadelphia region are listed on one website Polaris described as a popular registry for people seeking massage parlors where they can pay for sex. The site maps massage parlors and allows customers to leave reviews about the businesses and the women from whom they receive services. The parlors dot not just Philadelphia, but the collar counties, too: On a recent day, the site listed businesses in Bala Cynwyd, Bensalem, Downingtown, and other municipalities.
Because of the underground nature of the business, lack of resources for law enforcement, victims who may not realize they are victims, and a dearth of laws regulating massage businesses, sex trafficking can be underreported and tough to disrupt, experts say.
"It's much more challenging," said Jen Schorn, chief of trials in the Bucks County District Attorney's Office. "Our county detectives have done tremendous work in identifying and shutting down these illegal massage parlors, but obviously they pop up pretty frequently thereafter, and because of the language barrier and the cultural barrier, it makes it very hard."
Authorities have had some success. In 2016, investigators obtained prison terms for a Romanian couple who had forced vulnerable women to perform sex acts for customers at their massage parlors in two Bucks County municipalities. In September, three women were arrested on prostitution charges at a Center City massage parlor with a history of arrests. At another parlor in Philadelphia, police reportedly have made more than 25 arrests since 1998.
In recent years, awareness of human trafficking has increased along with a shift in thinking that treats women who are trafficked as victims rather than criminals. (Although men sometimes are trafficked for sex work, in most cases the victims are women.)
Among businesses suspected of being sex-trafficking fronts, massage parlors are second only to escort services in call volume to the trafficking hotline. Over the last several years, task forces and coalitions to fight human trafficking and raise awareness have been formed throughout the region to tackle a problem that often goes unrecognized or underreported.
In 2016, the national human trafficking hotline fielded more than 7,600 reports of trafficking, both from tipsters and victims. That same year, 156 trafficking cases were reported in Pennsylvania, according to hotline data.
"No area is immune," said Deirdre Blackburn, who coordinates efforts against human trafficking for the Network of Victim Assistance (NOVA) in Bucks County. "Often people think that it's less likely to happen in the suburbs and it's something that only happens in the cities, and that's really not the case. It really is everywhere."
Blackburn oversees the Bucks Coalition Against Trafficking, which has worked with county schools and hotels to train people to recognize human trafficking, along with advocating for legislation. They work with similar coalitions in all the surrounding counties, she said; it's common for trafficking to cross state and county lines.
Schorn, the Bucks prosecutor, said it's difficult to quantify how widespread the problem is.
"Every time there's a sting operation to go look for it, it's there. Always. If you have a hotel in your jurisdiction, it is there," she said. "It just takes knowing what the signs are to look for."
Victims are frequently moved through hotels, she said, and are often juvenile runaways or young women addicted to drugs.
In 2015, a 16-year-old girl from Rhode Island met a man who picked her up and took her to a hotel in New Jersey, where he had sex with her and then posted her photos in an advertisement for escort services. Not long after, Matthew Sipps, 40, of Delaware County, answered the ad and paid to have sex with the girl at a hotel, then took her to Aston and kept her in his home for a month before she was able to call her mother, who contacted police, according to investigators.
Last Wednesday, Sipps was ordered to serve one to five years in prison, the first sentence imposed in Delaware County under Pennsylvania's 2014 human trafficking law for engaging in a sex act while knowing it was with a victim of human trafficking. The man who advertised her as an "escort" is serving a federal prison term.
Pennsylvania's law has improved in recent years, Keyhan said, "but other states like California have strong provisions for the survivors and really well-developed laws that really talk through the nuances of trafficking and the way survivors are forced to do criminal acts."
Polaris, whose report did not identify by name suspected illicit massage parlors, is working with more than 100 law enforcement jurisdictions in 31 states to refine the approach to massage-business trafficking.
"The data [in the report are] a tool to encourage jurisdictions to stop doing undercover prostitution stings at illicit massage businesses and switch to more victim-centered, offender-focused investigations that target the organized criminal enterprises," Keyhan said, an approach she said has seen success in other cities such as Indianapolis.
Last year, Philadelphia authorities unveiled a human trafficking task force to focus on the issue.
Although Pennsylvania passed an improved human trafficking law in 2014, neither the state nor counties have the ordinances regulating massage businesses that Keyhan says could help prevent trafficking.
Only 24 incorporated towns in Pennsylvania have laws regulating massage business operations, such as requiring set business hours, keeping the front door unlocked, or not blacking out windows, Keyhan said.
The 100-page report by Polaris revealed new research into this type of human trafficking, one of 25 types identified and the first the group chose to research in such detail. It also estimated that illicit massage operators in the U.S. reap about $2.5 billion in annual revenue.
Trafficking survivors often are left with addiction, health-care and housing issues, and emotional trauma, Blackburn said.