Elizabeth Holmes Trial: Jim Mattis Tells Jury He Came to Doubt Theranos Technology

SAN JOSE, Calif.—Former Defense Secretary Jim Mattis testified Wednesday in the criminal trial of Theranos Inc. founder Elizabeth Holmes that he and other board members were blindsided to learn in 2015 that the company hadn’t been conducting all of its blood tests using its proprietary technology.

“There just came a point where I didn’t know what to believe about Theranos anymore,” the retired four-star general said.