A surgery technician accused of possibly exposing thousands of hospital patients to hepatitis C has pleaded guilty to some of the charges against her.

Kristen Diane Parker's plea Friday was part of an agreement with prosecutors that also calls for a 20-year prison term. She will be formally sentenced Dec. 11.

The 26-year-old previously pleaded not guilty to the 42-count indictment. But on Friday she pleaded guilty to five counts of tampering with a consumer product and five counts of obtaining a controlled substance by deceit or subterfuge.

Prosecutors say Parker stole syringes filled with painkillers to feed a drug habit and replaced them with syringes she used and refilled with saline solution at two hospitals.