By MICHAEL LIEDTKE
AP Technology Writer
SAN JOSE, Calif. (AP) — Biotechnology entrepreneur Elizabeth Holmes, a former billionaire accused of engineering a massive scam, expressed some remorse while on the witness stand Tuesday, but denied trying to conceal that her company’s blood-testing methods weren’t working as she had promised. In her third day of testimony during the high-profile criminal trial, Holmes acknowledged making some mistakes as CEO of Theranos, a company she founded in 2003 when she was just 19. But she repeatedly emphasized that she made most of her decisions with the help of other executives and a respected board that included former cabinet members in various presidential administrations.