Authorities have arrested a man in connection with the mysterious drug overdose incident that left three people dead and landed four others in the hospital in Pittsburgh on Sunday.

Peter Rene Sanchez Montalvo gave partygoers drugs that were found to be laced with fentanyl, leading to the overdoses, federal prosecutors said. He was taken into custody early Monday morning in McKees Rocks, Penn., a Pittsburgh suburb, and has been charged by the U.S. Attorney’s Office with federal drug charges of “possession with intent to distribute and distribution of a controlled substance causing death and serious bodily injury,” according to a criminal complaint.

The seven victims, all men, were found at or near a luxury South Side Pittsburgh apartment block early Sunday morning. Five were found in the apartment, one in an elevator, and another was found outside the building, police said. All seven men were wearing the same orange wristband.

The three dead have been identified as Rubiel Clemente-Martinez, 32, of Columbus; Joel Pecina, 32, of Coraopolis; and Josue Soberal Serrano, 38, of Carthage.

Police said they quickly identified two nearby events that were handing out orange wristbands to patrons. Sanchez Montalvo was at the one of those events, the Insomnia Discotec in the Brookline neighborhood of Pittsburgh, according to a police press release. Insomnia is an after-hours club frequented by members of the Hispanic community, according to the complaint.

At some point in the evening, Sanchez Montalvo left Insomnia and joined others who were also at the event for an “after-party” at the South Side apartment, according to the release.

“Sanchez-Montalvo distributed a white powdered substance, believed to be cocaine, to those in attendance. Shortly after, multiple people became seriously ill. Three of them died at the scene,” reads the press release.

Sanchez Montalvo allegedly produced a box with a large quantity of powdered narcotics that users believed to be cocaine. After cutting the narcotics, he began going around the room with a knife, “allowing individuals to sniff the white powder from it,” according to the Department of Justice press release. “The surviving users stated that after they did a ‘bump’ of suspected cocaine people immediately began to drop and suffer adverse effects,” reads the release.

An initial investigation by the Medical Examiner’s Office has determined that the deadly drug fentanyl was cut into the white powder.

According to officials, the overdoses appear to be an isolated incident, and the drugs were not passed around at the Insomnia event. Police, however, have warned the community that tainted drugs may still be in circulation.

According to the complaint, a man offered to pay a band that was performing at Insomnia Saturday night to play at his apartment after the show. The band, which is from Columbus, Ohio, allegedly agreed and accompanied him to the apartment where the overdoses occurred. The complaint does not state whether members of the band are amongst the victims.

Law enforcement interviewed the person who legally leased the apartment, who stated that they do not live there and do not have a key to the apartment. According to the complaint, that person said they were only renting the apartment as part of a deal brokered for two Hispanic males in exchange for $500 in compensation. According to the complaint, “renting apartments in other people’s names is a common tactic used by individuals involved in drug trafficking in an attempt to avoid detection by law enforcement.”

After Sanchez Montalvo’s arrest, law enforcement seized a California driver’s license with his name and likeness, as well as a “large amount of cash, cellular telephones, and packaging material typically associated with heroin trafficking,” according to the complaint. Officials also found a key fob and keys that allowed access to the building and apartment where the overdoses occurred.

According to the complaint, a witness who was present during the overdoses said Sanchez Montalvo “was bragging and showing off all the money that he had” prior to providing the drugs. This witness provided law enforcement with a video showing Sanchez Montalvo “showing off the money, cutting in to the kilo and scooping out the suspected cocaine, and serving the individuals in the apartment.”

Sanchez Montalvo is scheduled to make an appearance in federal court Monday afternoon. If convicted, he could face a sentence of no less than 20 years and up to life in prison, according to the U.S. Attorney’s Office.