McMillan was originally imprisoned in 2002 after pleading guilty to more than 20 years in federal prison for conspiracy to distribute methamphetamine in the state of Wyoming.
The federal case, and facts stated by Harkins during his pleas Wednesday, arose from a local investigation based on tips that he was using and selling illegal drugs at his home.
In March 2022, the Wyoming Division of Criminal Investigation opened an investigation into the suspected use and distribution of illicit controlled substances in Natrona County.