Jury selection in the criminal fraud trial of Elizabeth Holmes starts on Tuesday, the beginning of a highly anticipated legal showdown over one of the most spectacular Silicon Valley scandals in recent history.

Federal prosecutors have charged Holmes and her former business partner and ex-boyfriend, Ramesh "Sunny" Balwani, with defrauding investors and patients of their blood-testing company Theranos, which Holmes and Balwani claimed would revolutionize laboratory medicine.

Patients who were wrongly diagnosed by Theranos tests are set to testify against Holmes. Some had been told they were HIV-positive. Another, who was pregnant at the time, was incorrectly told she had miscarried her baby.