A judge Friday conveyed his disapproval over a plea agreement that would have sent Kristen Diane Parker - the former surgical technician at Denver's Rose Medical Centre accused of exposing hepatitis C infections among patients - to federal prison for 20 years.

The federal judge revealed that a 20 year imprisonment is not enough for the crime.

Parker had pleaded guilty under a plea agreement to account of acquisitions of fiddling with medications and obtaining a controlled substance.

Ms. Parker, 27, admitted her charges to the police on a videotape that while working at Rose Medical Centre in Denver in 2008 and 2009, she stole pain-medication syringes from operating room trays, replacing them sometimes with needles she had already used to inject herself with heroin thereby infecting dozens with hepatitis C.

U. S. District Judge Robert Blackburn's rejection over Parker's plea agreement signifies that now she could change her plea to not guilty and face trial, or on the other side she could stick to her guilty plea with Blackburn imposing the sentence.

One legal expert specializing in criminal law and sentencing, Douglas A. Berman, claimed that judges are generally unrelenting to impose out plea bargain agreements, partly because there is an assumption that victims have already been consulted.