The district attorney's office says a total of 12 women have come forward saying they are a victim of Andrew Gallo, of Bristol Township.
Of the victims, 10 of those women say they met him on a dating website and were given spiked drinks.
Investigators say Gallo would put drugs, including methamphetamine or Molly, into the victims' drinks without their knowledge.
The victims described feeling "strange" and having a "lack of control" during the ensuing sexual encounter, investigators say, adding that they were unable to stop Gallo.
Investigators say the victims described rough treatment, including Gallo putting his hands around the victims' throats to the point of passing out or almost passing out.
"The victims reported side effects from the drugs that included staying up for days, hallucinations, and psychosis," the office of D.A. Jennifer Schorn said in a news release in September.
He allegedly used the usernames DREWSTER420 and KAE, according to investigators.
Gallo is then accused of assaulting each of the women, who range in age from 17 to 30 years old.
During a search of his home earlier this year, police say they found a victim there at the time, along with a bottle of alcohol that had been laced with methamphetamine.
He is facing a list of charges, including rape by causing impairment, possession with intent to deliver a controlled substance, strangulation, selling or furnishing liquor or malt or brewed beverage to minors, and corruption of minors.
He was arrested in September and remains in custody.
After his arrest, authorities said they "strongly believe" there are more victims and are encouraging them to come forward.
If you have any information, you can contact Bristol Township Police Department Detective Emilyann Maialetti at 215-812-3024 or Bucks County Detectives at 215-348-6354. You can also contact Bucks County Detectives at bucksda.org, or the BucksCrimeTips submission email, buckscrimetips@buckscounty.org.