A group of gang members who trafficked drugs and guns and used dating websites to connect with people interested in hiring prostitutes were responsible for a series of robberies that led to four deaths, federal prosecutors said Friday.

Dubbed the “fentanyl robbery gang” (F.R.G.), the group worked from New Hampshire to Virginia, according to Gerard Karam, the U.S. attorney for the Middle District of Pennsylvania. He said the gang members and their associates would arrange to visit a victim’s location with the intent to rob them of guns, cash, cellphones, identification documents, debit and credit cards, drugs and other items of value.

The defendants were identified as Amanda Marie Correa, 29, Robert Andrew Barnes, 24, Christine Deann DiCarlo, 50, Shaqare Jaymont Blackwell, 23, Shakur Serafin Brownstein, 27, Dylan Wilson Small, 35, and Samual Jordan, 42.

Officials said the gang lured men into meeting a woman for a “date” by using dating apps such as “Plenty of Fish” and “MeetMe,” CBS affiliate WYOU reported.

Authorities said Correa, dubbed “Tiny,” is believed to be the leader of the gang and would arrange the “dates” while DiCarlo would show up with Correa, the station reported.

The victims would be offered drugs, usually purported cocaine, but were not told the narcotics contained fentanyl, authorities said. If victims refused the drugs, the gang members and/or their associates would forcibly administer them or surreptitiously introduce them it into their bodies, Karam said. This was done to incapacitate the victims so it was easier to steal from them.

“If a victim was not incapacitated, or not incapacitated quickly enough, members of the F.R.G. would instead change course and simply commit home-invasion robberies where they would be let into the victim’s home by other members and associates and then steal items of value at gunpoint or through other violent means, including threats, beatings, and aggravated assault,” prosecutors said.

The group is linked to three deaths in Pennsylvania – in Berks and Luzerne counties – and one in Portsmouth, New Hampshire, and prosecutors said it is likely there are other victims.

Seven group members have been indicted on numerous charges, including kidnapping, aggravated identity theft, conspiracy to distribute drugs, distributing fentanyl resulting in death and serious bodily injury and weapons charges. Some group members were affiliated with New York City gangs, Karam said.

The investigation involved several state, county and local law enforcement agencies in Pennsylvania and New Hampshire, as well as the FBI and the U.S. Marshal’s Service in Scranton, Pennsylvania.

The Drug Enforcement Administration says it seized over 79 million fake pills containing fentanyl in 2023, a more than 33% increase from the year before. To combat the crisis, officials are cracking down on drug traffickers by targeting online retailers selling pill presses.