Federal charges have been filed against a man for multiple fatal and non-fatal drug overdoses that left three people dead in Pittsburgh early Sunday.Federal law enforcement officials announced Monday that Peter Rene Sanchez Montalvo, also known as Carlos, was arrested early Monday morning near Pittsburgh.Montalvo is charged with possession with the intent to distribute and distribution of a controlled substance causing death and serious bodily injury.According to an affidavit, the overdoses occurred after Montalvo distributed narcotics at an apartment on the South Side.Police said Montalvo left a bar with several people, including members of the band that played there Saturday night, to join him for what was described as an "after-party."According to the complaint, during the party, Montalvo produced a large quantity of powdered narcotics in a box. He then cut into the narcotics and scooped out a large quantity of what the users believed was cocaine. Montalvo then started going around the room with the knife, allowing individuals to sniff the white powder from it. The surviving users stated that after they did a “bump” of suspected cocaine, people immediately began to drop and suffer adverse effects.An investigation by the Allegheny County Medical Examiner’s Office initially determined the presence of fentanyl in the white powder. Police and first responders entered an apartment building and found one man dead outside an elevator. Five additional victims were located inside the apartment: two dead men and three men suffering from a medical emergency, the latter of whom were transported to a hospital. The Allegheny County medical examiner identified the dead as Rubiel Clemente-Martinez, 32, of Columbus, Ohio; Josue Soberal Serrano, 38, of Carthage, Missouri; and Joel Pecina, 32, of Coraopolis, Pennsylvania.All of the people found by first responders were wearing orange wrist bands, prompting initial concerns that the health emergency may have started at a concert or event venue."To be clear, this was not a case of a tainted drug being passed around or distributed in large volume at a large venue which could have affected even more people. It appears to have been isolated to a single location," Pittsburgh police spokesman Chris Togneri said."Anyone who attended one of these events (with orange wrist bands) has no cause for concern regarding their health."Montalvo was set to make an initial appearance in federal court Monday afternoon.CNN contributed to this report.