OKLAHOMA CITY - Two Oklahoma men have pleaded guilty to federal charges after prosecutors said they distributed pills containing a synthetic opioid that resulted in at least one person's death.

Collin Shane Kirby, 21, of Oklahoma City, and Shane Michael Burgess, 24, of Mustang, each pleaded guilty to distributing a controlled substance analogue, according to U.S. Attorney Robert J. Troester.

Federal court records show that on Dec. 12, 2025, Kirby sold Burgess pills containing N-Propionitrile Chlorphine, a synthetic opioid also known as cychlorphine.

Burgess then resold the pills to another person later that same day, prosecutors said.

That person died after using the cychlorphine distributed by Kirby and Burgess, according to court records.

Kirby and Burgess were charged in separate superseding informations in July and August. Both have since admitted their roles in distributing the synthetic opioid that ultimately resulted in at least one death.

Federal prosecutors said Kirby also admitted distributing cychlorphine to a minor on Feb. 7, 2026.

Kirby and Burgess each face up to 20 years in federal prison and a fine of up to $1 million when sentenced.

The Drug Enforcement Administration and the Oklahoma Bureau of Narcotics and Dangerous Drugs investigated the cases. Assistant U.S. Attorney Elizabeth Joynes is prosecuting.