(KRON) — A San Jose man accused of selling fake “M30” pills that killed one of his buyers in Fremont was taken into custody on Thursday.

Ian Edward Parrish, 28, of San Jose, made his first court appearance in Oakland before U.S. Judge Kandis Westmore. The judge remanded Parrish into custody.

According to a criminal complaint, Parrish sold two counterfeit Percocet pills to a person in a bar in Fremont. “The counterfeit pills were, in fact, laced with fentanyl,” prosecutors wrote.

After consuming just one pill, the person overdosed and died. Parrish was later arrested and charged with distributing fentanyl. If convicted, he faces up to 20 years in prison.

The DEA has an ongoing anti-drug campaign, “One Pill Can Kill.”

Fentanyl, a highly potent opiate, if often diluted by drug dealers with cutting agents to create counterfeit pills that purport to mimic the effects of Oxycodone, Percocet, and other drugs. However, very small variations in the amount or quality of fentanyl create huge effects on the potency of the counterfeit pills, and can easily cause death, prosecutors said. 

Fentanyl-laced counterfeit pills are usually shaped and colored to resemble pills that are sold at pharmacies. Fentanyl was the leading cause of drug overdose deaths in the United States last year. 

Parrish’s next court appearance is scheduled for March 21. Assistant U.S. Attorney Evan Mateer of the Oakland Branch of the United States Attorney’s Office is prosecuting the case. The prosecution is the result of an investigation by FBI and the Fremont Police Department.