SAN JOSE, Calif. (KRON) — For three days on the witness stand, Elizabeth Holmes painted a flattering self-portrait about what she accomplished as an inventor, a visionary for better healthcare, and a young Silicon Valley CEO.

Holmes, 37, was poised, articulate, and self-confident testifying at her own criminal fraud trial.

With her future on the line and facing possible prison time, Holmes did her best to convince the jury that she is a good person with good intentions. When she founded her biotech company, Theranos, her goal was to save lives through revolutionizing blood testing.

Federal prosecutors charged Holmes with defrauding wealthy investors who pumped millions of dollars into Theranos. Ex-Theranos employees testified earlier in the trial that Holmes’ $9-billion company was built with smoke and mirrors.

Elizabeth Holmes arrives for her criminal fraud trial
Elizabeth Holmes arrives for her criminal fraud trial holding her mother’s hand. (Justin Sullivan / Getty Images)

A big surprise happened in court Tuesday when she admitted to the jury that she made one mistake.

As part of her pitch for opening wellness centers in Walgreens pharmacies, Holmes gave Walgreens executives reports on Theranos technology in 2010. The report included a Pfizer logo at the top, giving the impression Pfizer endorsed the new technology’s accuracy.

A Pfizer company executive previously testified that Holmes was never authorized to use the pharmaceutical company’s logo or endorsement.

Defense attorney Kevin Downey asked Holmes, who added Pfizer’s logo to the report?

She answered, “I did, just before sending them to Walgreens.”

“I wish I had done it differently,” Holmes testified.

Prosecutors had highlighted the reports as evidence of deception.

Walgreens opened Theranos wellness centers in 2013 and some patients experienced major health scares after receiving inaccurate test results.

Holmes’ confidence in her invention came from scientists who told her Theranos’ blood testing machines could run a wide range of tests with speed and accuracy. One scientist who was mentioned several times was Dr. Ian Gibbons, a biochemist and Theranos’ chief scientist.

Downey showed an email Gibbons sent to Holmes in 2010.

“I think we have demonstrated capabilities fully equivalent to (traditional) lab methods. Our immuno-assays match the best that can be done in clinical labs and work with small blood samples,” Gibbons wrote.

Holmes will return to the witness stand for direct examinations when her trial resumes on Monday.

Elizabeth Holmes
Theranos founder Elizabeth Holmes goes through a security checkpoint as she arrives for her trial. (Photo by Justin Sullivan/Getty Images)