The teenager woke up after a night of partying at a Providence, R.I., house to find herself naked in a shower, surrounded by men who were laughing and taking pictures, the police said.
She went to the police almost immediately, but the case stalled with little to go on beyond the girl’s painful memories from that night in December. Then, in March, the girl’s mother found a video of her daughter being sexually assaulted that one of the perpetrators had posted on Facebook.
The mother took out her phone, recorded the video on her computer screen and sent the recording to the police.
“That’s when the investigation really heated up,” Maj. David Lapatin of the Providence Police Department said in an interview on Wednesday. “We were able to see who was there. We were able to see faces. We were able to see the actual act, of first-degree sexual assault.”
On Wednesday, the police said the mother’s discovery of the Facebook video helped them charge eight men with sexually assaulting the 16-year-old girl after she lost consciousness at the house party on Dec. 20, 2019.
Col. Hugh T. Clements Jr., chief of the Providence police, said the assault was one of the worst he could recall in his 35 years with the department.
“The incident is horrifying, devastating, disturbing on so many levels to this young girl, to her family and to this community,” Chief Clements said at a news conference.
He said the teenager had been offered counseling, housing and other services, and he thanked her and her family for coming forward to report the crime. Not only had she helped identify the men who assaulted her, he said, but she also faced the possibility of testifying in court and being sharply questioned by defense lawyers.
“I commend her bravery, her courage and her family for sticking by her,” the chief said.
“I give her a lot of credit,” he added.
The police said six men — Keith Erving Colon, 24; Jose Vargas, 18; Carlos Chacon, 19; Malcolm Baptista, 18; Luis A. Cabrera, 18; and Luis Luna, 19 — were arrested last week and charged with assault with intent to commit sexual assault and conspiracy.
A seventh man, Richard Tarell Chester, 19, was arrested and charged with first-degree sexual assault, the police said. The eighth, Carlos D. Vasquez, was being sought on Wednesday on charges of assault with intent to commit sexual assault and conspiracy.
Lawyers for several of the men did not immediately respond to messages on Wednesday. Chad F. Bank, a lawyer for Mr. Luna, and Nicholas Obolensky, a lawyer for Mr. Cabrera, declined to comment.
The teenager had been invited to the party by two boys she knew, Major Lapatin said. She remembered drinking and smoking marijuana and then not feeling well, so she went to a bedroom to lie down, he said. That’s when someone forced her to drink more alcohol, causing her to lose consciousness, she later told the police.
When she awoke, she was naked in the shower, surrounded by eight to 15 men, Major Lapatin said.
The teenager left the party and went to the hospital with pain in her genital area, Major Lapatin said. She then gave a full statement to the police, he said.
“She was able to give us some names of who was there,” he said, “but we didn’t have the evidence right then to start charging people.”
The investigation accelerated, he said, when someone told the girl’s mother about the video of the assault on Facebook.
Detectives recognized several of the men’s faces and nicknames in the video, he said, and were able to track them down.
The sharing of the video on Facebook suggests the perpetrators were “proud of what they had done and wanted to display this for others to see — and that in itself is disturbing,” said Vanessa Volz, the executive director of Sojourner House, in Providence, which provides emergency housing, counseling and other services to victims of sexual violence and their families.
“It’s obviously horrific and completely unacceptable and I think very indicative of how we still are living in a rape culture,” Ms. Volz said.
Many of those who seek help at Sojourner House have been harassed, tracked or shamed online and on social media, Ms. Volz said.
“There’s a dehumanization element with the technology we have access to,” she said. “It’s so easy. You videotape something, you copy it, you send it. It happens so instantaneously. You can do all that in less than a minute.”
She said the case reinforced the need to change deep-seated cultural attitudes about how people treat each other. “And until that changes,” she said, “we’re going to continue to see these types of incidents.”