AUSTIN (KXAN) – An Austin man pleaded guilty in federal court on Tuesday to distribution of fentanyl causing death, according to the U.S. Department of Justice.

According to court documents cited by the U.S. Attorney’s Office of the Western District of Texas, David Lee Jr., 46, was identified as a supplier of counterfeit oxycodone tablets and other counterfeit prescription pills in the investigation of the overdose death of an 18-year-old Coupland man. 

The office said as part of the investigation, a Williamson County Sheriff’s Office investigator purchased eight oxycodone tablets from Lee. A laboratory analysis determined the tablets contained fentanyl, tramadol and florofentanyl. 

Lee then initiated a subsequent sale of 1,000 oxycodone tablets to the investigator, according to the attorney’s office. The lab analysis from that controlled-buy revealed the tablets contained fentanyl. 

Lee faced a penalty of 20 years to life in prison, according to Thursday’s announcement. A federal district court judge will determine any sentence after considering the U.S. Sentencing Guidelines and other statutory factors.

The Drug Enforcement Administration, Williamson County Sheriff’s Office and Guadalupe County Sheriff’s Office were investigating the case.