JACKSONVILLE, Fla. -- Steven Beumel, 48, is responsible for spreading Hepatitis C at Mayo clinic. He pleaded guilty Thursday to one count of tampering with a consumer product resulting in death, four counts of tampering with a consumer product resulting in serious bodily injury, and five counts of stealing Fentanyl by deception.

Beumel, a radiology technician before Mayo clinic fired him, faces a maximum penalty of life in federal prison. He has remained in custody since FBI agents arrested him in May 2011. A sentencing date has not been scheduled.

Buemel admitted in court that he stole syringes of Fentanyl during patients' procedures and replaced them with syringes of saline contaminated with Hepatitis C. His tampering occured from 2006-2008 at Mayo Clinic's interventional radiology unit.

The Clinic tested thousands of patients who Beumel potentially put at risk. It linked two patients from that effort to Beumel - the first was a liver transplant patient. He battled Hepatitis C for almost four years until he died from complications related to the disease, never knowing how he got it.